In a large, heavy-bottomed pot, heat the olive oil over medium heat until shimmering. Add the Italian sausage and break it apart with a wooden spoon. Cook, stirring frequently, until the sausage is browned and cooked through, approximately 5 to 7 minutes.
Next, add the finely diced onion, minced garlic, peeled and diced carrots, and diced celery to the pot. Sauté the mixture for about 5 minutes, or until the vegetables are tender and fragrant.
Pour in the chicken broth and increase the heat to high, bringing the mixture to a rolling boil. Once boiling, add the ditalini pasta and reduce the heat to medium. Cook according to the package instructions until the pasta is al dente, usually about 8 to 10 minutes.
After the pasta is cooked to your liking, lower the heat and stir in the heavy cream and grated Parmesan cheese. Mix well until the cheese melts into the soup.
Season with the dried thyme, oregano, salt, and freshly ground black pepper to taste. Allow the soup to simmer gently for an additional 5 minutes.
Remove the pot from heat. Garnish each bowl with a sprinkle of freshly chopped parsley before serving.
Notes
For a richer flavor, use freshly grated Parmesan cheese and serve with crusty bread.