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Crockpot French Onion Soup Simple and Rich Delight

by on August 16, 2025
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Are you ready to dive into a cozy bowl of Crockpot French Onion Soup? This simple recipe will wrap you in warmth, with rich flavors from just a few main ingredients. Imagine sweet, caramelized onions, melty cheese, and fragrant herbs simmering slowly in your crockpot. With straightforward steps and helpful tips, I’ll guide you through making this classic dish easy and delightful. Let’s get cooking and create some comfort in a bowl!

- 4 large yellow onions, thinly sliced - 4 cloves garlic, minced - 4 cups low-sodium beef broth - 1 cup vegetable broth French onion soup shines with its simple yet rich flavor. The star of this dish is the yellow onion. When cooked slowly, it becomes sweet and deeply flavorful. You will need four large yellow onions. Slice them thinly to help them cook evenly. Garlic adds a nice punch. Four cloves, minced, will do the trick. Next, the broth. Four cups of low-sodium beef broth create a savory base. If you prefer a lighter taste, add one cup of vegetable broth. This mix gives depth without overpowering the sweet onions. - 2 cups shredded Gruyère cheese - 1 cup shredded mozzarella cheese Cheese is key to a great French onion soup. Gruyère cheese is the classic choice. Its nutty flavor melts beautifully over the soup. You need two cups of shredded Gruyère. To add a stretchy texture, use one cup of mozzarella cheese. This combination makes each bite rich and creamy. - 1 tablespoon olive oil - 1 tablespoon unsalted butter - 2 teaspoons dried thyme - 1 teaspoon granulated sugar - Salt and freshly ground black pepper to taste The right seasonings enhance the soup's flavor. Start with one tablespoon of olive oil and one tablespoon of unsalted butter. This blend helps caramelize the onions. Add two teaspoons of dried thyme for a herby note. A teaspoon of granulated sugar helps caramelize the onions further, balancing their flavor. Lastly, season with salt and freshly ground black pepper to taste. Adjust these to your liking. A pinch here or there can make all the difference! First, I heat a large skillet over medium heat. I add one tablespoon of olive oil and one tablespoon of unsalted butter. Once the butter melts, I toss in four large yellow onions that I have thinly sliced. I cook these onions for about ten minutes, stirring now and then. I want them to soften up a bit. Next, I add four minced garlic cloves and one teaspoon of granulated sugar to the skillet. The sugar helps the onions caramelize nicely. I keep cooking them for about 15 to 20 minutes. I stir often, watching for that beautiful golden brown color. This step brings out their sweet flavor, making the soup rich and tasty. Once my onions are caramelized, I transfer them to the crockpot. Then, I pour in four cups of low-sodium beef broth and one cup of vegetable broth. I sprinkle in two teaspoons of dried thyme, adding even more flavor. Next, I season the mix with salt and freshly ground black pepper to taste. I gently stir everything together until it is well combined. Now, I cover the crockpot with its lid. I set it to cook on low heat for six to eight hours. If I am in a hurry, I can set it on high for three to four hours instead. Slow cooking is key here; it allows all those flavors to blend and deepen. After the cooking time is up, I taste the soup to check the seasoning. If it needs more salt or pepper, I add a little more to fit my taste. This simple step ensures that my French onion soup is just right before serving. To get that rich, sweet flavor, timing is key. Start cooking the onions on medium heat. Stir them often to help them cook evenly. This will take about 25 to 30 minutes. If you see them starting to burn, lower the heat. You want them golden brown, not black. Want to boost the taste? Try adding herbs like rosemary or bay leaves. These can add depth to your soup. You can also mix broth types. Using chicken broth with beef broth can give a nice twist. Feel free to adjust the salt and pepper to fit your taste. The best bread for this soup is a French baguette. Slice it into thick pieces. After broiling, the bread becomes crunchy and perfect for soaking up the soup. For garnish, use fresh thyme sprigs. They add a pop of color and flavor. Serve in oven-safe bowls for a fun touch. {{image_4}} To make this soup vegetarian, swap the beef broth for vegetable broth. This simple change keeps the flavor rich and hearty. For the cheese, you can use a blend of mozzarella and a creamy cheese like fontina. Both options melt well and add a nice touch. While Gruyère is a classic choice, you can experiment with other cheeses. Try using sharp cheddar for a bolder taste. Provolone adds a nice stretch, and even goat cheese can bring a tangy flair. Just remember to choose cheeses that melt well. You can boost this soup's flavor by adding proteins or vegetables. Shredded chicken or cooked lentils work great for extra protein. If you want to add veggies, consider mushrooms or spinach. Both add nutrients and depth. Just mix them in with the onions while they cook for an even more flavorful dish. How long does it last? You can keep your Crockpot French onion soup in the fridge for about 3 to 4 days. Make sure it cools down first. This will help keep it fresh. Proper container recommendations? Use an airtight container. Glass or plastic works well. This keeps out air and helps avoid any bad smells. Best practices for freezing soup? If you want to freeze your soup, let it cool completely. Pour it into freezer-safe bags or containers. Leave some space at the top. This allows for expansion when it freezes. Thawing and reheating tips? When you want to eat it, take the soup out of the freezer. Move it to the fridge for a day to thaw. You can also thaw it in a bowl of cold water. For reheating, use a pot on low heat. Stir often to avoid burning. Creative ways to use leftover soup? You can turn your soup into a tasty risotto or pasta sauce. Just add some cooked rice or pasta to it. Top it with more cheese and broil until bubbly. You can also use it as a base for a savory stew. Just add vegetables or meat for a new meal! Yes, you can use other onions. Sweet onions, like Vidalia, work well. Red onions add a slight tang. Each type of onion gives a unique taste. Try using shallots for a milder flavor. Remember, the key is to caramelize them properly. Caramelization brings out the sweet flavor you want in the soup. You can store leftover soup for up to five days in the fridge. Make sure to use an airtight container. This keeps the soup fresh and tasty. If you want to keep it longer, consider freezing it. Frozen soup lasts up to three months. Just remember to cool it completely before freezing. This helps prevent ice crystals from forming. Reheat the soup on the stove for best results. Use low heat and stir often. This prevents the soup from sticking to the pot. You can also use the microwave. Heat it in short bursts, stirring in between. This helps the soup heat evenly. If you want to enjoy your soup like fresh, place cheesy toast on top just before serving! This blog covered how to make delicious French onion soup. We discussed key ingredients like onions, garlic, and broth. We explored cheese choices and how to season your soup perfectly. The step-by-step guide helped with caramelizing and combining the ingredients. Tips for perfecting flavor and variations offered fun twists. Lastly, we talked about storage and reheat methods. Enjoy your cooking adventure with this classic dish!

Ingredients

Main Ingredients

– 4 large yellow onions, thinly sliced

– 4 cloves garlic, minced

– 4 cups low-sodium beef broth

– 1 cup vegetable broth

French onion soup shines with its simple yet rich flavor. The star of this dish is the yellow onion. When cooked slowly, it becomes sweet and deeply flavorful. You will need four large yellow onions. Slice them thinly to help them cook evenly. Garlic adds a nice punch. Four cloves, minced, will do the trick.

Next, the broth. Four cups of low-sodium beef broth create a savory base. If you prefer a lighter taste, add one cup of vegetable broth. This mix gives depth without overpowering the sweet onions.

Cheese Selection

– 2 cups shredded Gruyère cheese

– 1 cup shredded mozzarella cheese

Cheese is key to a great French onion soup. Gruyère cheese is the classic choice. Its nutty flavor melts beautifully over the soup. You need two cups of shredded Gruyère. To add a stretchy texture, use one cup of mozzarella cheese. This combination makes each bite rich and creamy.

Seasonings and Condiments

– 1 tablespoon olive oil

– 1 tablespoon unsalted butter

– 2 teaspoons dried thyme

– 1 teaspoon granulated sugar

– Salt and freshly ground black pepper to taste

The right seasonings enhance the soup’s flavor. Start with one tablespoon of olive oil and one tablespoon of unsalted butter. This blend helps caramelize the onions. Add two teaspoons of dried thyme for a herby note. A teaspoon of granulated sugar helps caramelize the onions further, balancing their flavor.

Lastly, season with salt and freshly ground black pepper to taste. Adjust these to your liking. A pinch here or there can make all the difference!

Step-by-Step Instructions

Preparing the Onions

First, I heat a large skillet over medium heat. I add one tablespoon of olive oil and one tablespoon of unsalted butter. Once the butter melts, I toss in four large yellow onions that I have thinly sliced. I cook these onions for about ten minutes, stirring now and then. I want them to soften up a bit.

Next, I add four minced garlic cloves and one teaspoon of granulated sugar to the skillet. The sugar helps the onions caramelize nicely. I keep cooking them for about 15 to 20 minutes. I stir often, watching for that beautiful golden brown color. This step brings out their sweet flavor, making the soup rich and tasty.

Combining the Ingredients

Once my onions are caramelized, I transfer them to the crockpot. Then, I pour in four cups of low-sodium beef broth and one cup of vegetable broth. I sprinkle in two teaspoons of dried thyme, adding even more flavor. Next, I season the mix with salt and freshly ground black pepper to taste. I gently stir everything together until it is well combined.

Cooking Process

Now, I cover the crockpot with its lid. I set it to cook on low heat for six to eight hours. If I am in a hurry, I can set it on high for three to four hours instead. Slow cooking is key here; it allows all those flavors to blend and deepen.

After the cooking time is up, I taste the soup to check the seasoning. If it needs more salt or pepper, I add a little more to fit my taste. This simple step ensures that my French onion soup is just right before serving.

Tips & Tricks

Perfecting the Caramelization

To get that rich, sweet flavor, timing is key. Start cooking the onions on medium heat. Stir them often to help them cook evenly. This will take about 25 to 30 minutes. If you see them starting to burn, lower the heat. You want them golden brown, not black.

Enhancing Flavor

Want to boost the taste? Try adding herbs like rosemary or bay leaves. These can add depth to your soup. You can also mix broth types. Using chicken broth with beef broth can give a nice twist. Feel free to adjust the salt and pepper to fit your taste.

Serving Suggestions

The best bread for this soup is a French baguette. Slice it into thick pieces. After broiling, the bread becomes crunchy and perfect for soaking up the soup. For garnish, use fresh thyme sprigs. They add a pop of color and flavor. Serve in oven-safe bowls for a fun touch.

Variations

Vegetarian Adaptation

To make this soup vegetarian, swap the beef broth for vegetable broth. This simple change keeps the flavor rich and hearty. For the cheese, you can use a blend of mozzarella and a creamy cheese like fontina. Both options melt well and add a nice touch.

Different Cheese Options

While Gruyère is a classic choice, you can experiment with other cheeses. Try using sharp cheddar for a bolder taste. Provolone adds a nice stretch, and even goat cheese can bring a tangy flair. Just remember to choose cheeses that melt well.

Additional Ingredients

You can boost this soup’s flavor by adding proteins or vegetables. Shredded chicken or cooked lentils work great for extra protein. If you want to add veggies, consider mushrooms or spinach. Both add nutrients and depth. Just mix them in with the onions while they cook for an even more flavorful dish.

Storage Info

Refrigeration Guidelines

How long does it last? You can keep your Crockpot French onion soup in the fridge for about 3 to 4 days. Make sure it cools down first. This will help keep it fresh.

Proper container recommendations? Use an airtight container. Glass or plastic works well. This keeps out air and helps avoid any bad smells.

Freezing Instructions

Best practices for freezing soup? If you want to freeze your soup, let it cool completely. Pour it into freezer-safe bags or containers. Leave some space at the top. This allows for expansion when it freezes.

Thawing and reheating tips? When you want to eat it, take the soup out of the freezer. Move it to the fridge for a day to thaw. You can also thaw it in a bowl of cold water. For reheating, use a pot on low heat. Stir often to avoid burning.

Leftover Ideas

Creative ways to use leftover soup? You can turn your soup into a tasty risotto or pasta sauce. Just add some cooked rice or pasta to it. Top it with more cheese and broil until bubbly. You can also use it as a base for a savory stew. Just add vegetables or meat for a new meal!

FAQs

Can I use a different type of onion?

Yes, you can use other onions. Sweet onions, like Vidalia, work well. Red onions add a slight tang. Each type of onion gives a unique taste. Try using shallots for a milder flavor. Remember, the key is to caramelize them properly. Caramelization brings out the sweet flavor you want in the soup.

How long can I store leftover French onion soup?

You can store leftover soup for up to five days in the fridge. Make sure to use an airtight container. This keeps the soup fresh and tasty. If you want to keep it longer, consider freezing it. Frozen soup lasts up to three months. Just remember to cool it completely before freezing. This helps prevent ice crystals from forming.

What is the best way to reheat the soup?

Reheat the soup on the stove for best results. Use low heat and stir often. This prevents the soup from sticking to the pot. You can also use the microwave. Heat it in short bursts, stirring in between. This helps the soup heat evenly. If you want to enjoy your soup like fresh, place cheesy toast on top just before serving!

This blog covered how to make delicious French onion soup. We discussed key ingredients like onions, garlic, and broth. We explored cheese choices and how to season your soup perfectly. The step-by-step guide helped with caramelizing and combining the ingredients. Tips for perfecting flavor and variations offered fun twists. Lastly, we talked about storage and reheat methods. Enjoy your cooking adventure with this classic dish!

- 4 large yellow onions, thinly sliced - 4 cloves garlic, minced - 4 cups low-sodium beef broth - 1 cup vegetable broth French onion soup shines with its simple yet rich flavor. The star of this dish is the yellow onion. When cooked slowly, it becomes sweet and deeply flavorful. You will need four large yellow onions. Slice them thinly to help them cook evenly. Garlic adds a nice punch. Four cloves, minced, will do the trick. Next, the broth. Four cups of low-sodium beef broth create a savory base. If you prefer a lighter taste, add one cup of vegetable broth. This mix gives depth without overpowering the sweet onions. - 2 cups shredded Gruyère cheese - 1 cup shredded mozzarella cheese Cheese is key to a great French onion soup. Gruyère cheese is the classic choice. Its nutty flavor melts beautifully over the soup. You need two cups of shredded Gruyère. To add a stretchy texture, use one cup of mozzarella cheese. This combination makes each bite rich and creamy. - 1 tablespoon olive oil - 1 tablespoon unsalted butter - 2 teaspoons dried thyme - 1 teaspoon granulated sugar - Salt and freshly ground black pepper to taste The right seasonings enhance the soup's flavor. Start with one tablespoon of olive oil and one tablespoon of unsalted butter. This blend helps caramelize the onions. Add two teaspoons of dried thyme for a herby note. A teaspoon of granulated sugar helps caramelize the onions further, balancing their flavor. Lastly, season with salt and freshly ground black pepper to taste. Adjust these to your liking. A pinch here or there can make all the difference! First, I heat a large skillet over medium heat. I add one tablespoon of olive oil and one tablespoon of unsalted butter. Once the butter melts, I toss in four large yellow onions that I have thinly sliced. I cook these onions for about ten minutes, stirring now and then. I want them to soften up a bit. Next, I add four minced garlic cloves and one teaspoon of granulated sugar to the skillet. The sugar helps the onions caramelize nicely. I keep cooking them for about 15 to 20 minutes. I stir often, watching for that beautiful golden brown color. This step brings out their sweet flavor, making the soup rich and tasty. Once my onions are caramelized, I transfer them to the crockpot. Then, I pour in four cups of low-sodium beef broth and one cup of vegetable broth. I sprinkle in two teaspoons of dried thyme, adding even more flavor. Next, I season the mix with salt and freshly ground black pepper to taste. I gently stir everything together until it is well combined. Now, I cover the crockpot with its lid. I set it to cook on low heat for six to eight hours. If I am in a hurry, I can set it on high for three to four hours instead. Slow cooking is key here; it allows all those flavors to blend and deepen. After the cooking time is up, I taste the soup to check the seasoning. If it needs more salt or pepper, I add a little more to fit my taste. This simple step ensures that my French onion soup is just right before serving. To get that rich, sweet flavor, timing is key. Start cooking the onions on medium heat. Stir them often to help them cook evenly. This will take about 25 to 30 minutes. If you see them starting to burn, lower the heat. You want them golden brown, not black. Want to boost the taste? Try adding herbs like rosemary or bay leaves. These can add depth to your soup. You can also mix broth types. Using chicken broth with beef broth can give a nice twist. Feel free to adjust the salt and pepper to fit your taste. The best bread for this soup is a French baguette. Slice it into thick pieces. After broiling, the bread becomes crunchy and perfect for soaking up the soup. For garnish, use fresh thyme sprigs. They add a pop of color and flavor. Serve in oven-safe bowls for a fun touch. {{image_4}} To make this soup vegetarian, swap the beef broth for vegetable broth. This simple change keeps the flavor rich and hearty. For the cheese, you can use a blend of mozzarella and a creamy cheese like fontina. Both options melt well and add a nice touch. While Gruyère is a classic choice, you can experiment with other cheeses. Try using sharp cheddar for a bolder taste. Provolone adds a nice stretch, and even goat cheese can bring a tangy flair. Just remember to choose cheeses that melt well. You can boost this soup's flavor by adding proteins or vegetables. Shredded chicken or cooked lentils work great for extra protein. If you want to add veggies, consider mushrooms or spinach. Both add nutrients and depth. Just mix them in with the onions while they cook for an even more flavorful dish. How long does it last? You can keep your Crockpot French onion soup in the fridge for about 3 to 4 days. Make sure it cools down first. This will help keep it fresh. Proper container recommendations? Use an airtight container. Glass or plastic works well. This keeps out air and helps avoid any bad smells. Best practices for freezing soup? If you want to freeze your soup, let it cool completely. Pour it into freezer-safe bags or containers. Leave some space at the top. This allows for expansion when it freezes. Thawing and reheating tips? When you want to eat it, take the soup out of the freezer. Move it to the fridge for a day to thaw. You can also thaw it in a bowl of cold water. For reheating, use a pot on low heat. Stir often to avoid burning. Creative ways to use leftover soup? You can turn your soup into a tasty risotto or pasta sauce. Just add some cooked rice or pasta to it. Top it with more cheese and broil until bubbly. You can also use it as a base for a savory stew. Just add vegetables or meat for a new meal! Yes, you can use other onions. Sweet onions, like Vidalia, work well. Red onions add a slight tang. Each type of onion gives a unique taste. Try using shallots for a milder flavor. Remember, the key is to caramelize them properly. Caramelization brings out the sweet flavor you want in the soup. You can store leftover soup for up to five days in the fridge. Make sure to use an airtight container. This keeps the soup fresh and tasty. If you want to keep it longer, consider freezing it. Frozen soup lasts up to three months. Just remember to cool it completely before freezing. This helps prevent ice crystals from forming. Reheat the soup on the stove for best results. Use low heat and stir often. This prevents the soup from sticking to the pot. You can also use the microwave. Heat it in short bursts, stirring in between. This helps the soup heat evenly. If you want to enjoy your soup like fresh, place cheesy toast on top just before serving! This blog covered how to make delicious French onion soup. We discussed key ingredients like onions, garlic, and broth. We explored cheese choices and how to season your soup perfectly. The step-by-step guide helped with caramelizing and combining the ingredients. Tips for perfecting flavor and variations offered fun twists. Lastly, we talked about storage and reheat methods. Enjoy your cooking adventure with this classic dish!

Crockpot French Onion Soup

Warm up with a bowl of Slow-Cooked Savory French Onion Soup! This delicious recipe combines caramelized onions, rich beef broth, and melted Gruyère cheese topped with crunchy baguette slices for the ultimate comfort food. Easy to prepare in your crockpot, it's perfect for any occasion. Don't miss out on this mouthwatering dish. Click through to discover the full recipe and savor every bite!
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Ingredients
  

4 large yellow onions, thinly sliced

4 cloves garlic, minced

4 cups low-sodium beef broth

1 cup vegetable broth

1 tablespoon olive oil

1 tablespoon unsalted butter

2 teaspoons dried thyme

1 teaspoon granulated sugar

Salt and freshly ground black pepper to taste

1 French baguette, sliced into 1-inch pieces

2 cups shredded Gruyère cheese

1 cup shredded mozzarella cheese

Instructions
 

Start by heating a large skillet over medium heat. Once hot, add the olive oil and unsalted butter. After the butter has melted, add the thinly sliced onions. Cook the onions for about 10 minutes, stirring occasionally, until they begin to soften. Then add the minced garlic and granulated sugar, continuing to cook for an additional 15-20 minutes. Stir frequently until the onions are deeply caramelized and golden brown, enhancing their natural sweetness.

    Once the onions are caramelized, transfer them along with the garlic to your crockpot. Pour in the low-sodium beef broth and vegetable broth. Sprinkle in the dried thyme, and season with salt and freshly ground black pepper. Gently stir everything together until well combined.

      Cover the crockpot with its lid and set it to cook on low heat for 6-8 hours. If you're short on time, you can cook it on high for 3-4 hours. This long and slow cooking allows the flavors to meld beautifully.

        After the cooking time has elapsed, taste the soup and adjust the seasoning if necessary, adding more salt and pepper to suit your palate.

          When you're ready to serve, preheat your oven to the broil setting. Arrange the baguette slices on a baking sheet. Generously sprinkle the Gruyère and mozzarella cheese over each slice. Broil the cheese-covered baguette slices for 2-3 minutes, watching closely until the cheese is bubbly and turns a delightful golden color.

            To serve, ladle the hot soup into bowls and place a cheesy toast slice directly on top of each serving, allowing the cheese to slightly melt into the soup.

              Prep Time: 20 minutes | Total Time: 6-8 hours | Servings: 6

                - Presentation Tips: For an elegant presentation, serve the soup in oven-safe bowls. Garnish with freshly sprigs of thyme, adding a touch of freshness and color to your dish. Enjoy the comforting warmth of this hearty soup!