In a large pot, cook the Italian sausage over medium heat until browned, breaking it apart with a spoon.

Add the diced onion, garlic, carrots, and celery to the pot and sauté until the vegetables are softened, about 5 minutes.

Pour in the chicken broth and add the diced potatoes. Bring to a boil, then reduce heat and simmer for 15-20 minutes until potatoes are tender.

Stir in the heavy cream, shredded cheddar cheese, salt, pepper, and thyme. Cook until the cheese is melted and the soup is heated through, about 5 minutes.

Taste and adjust seasoning if necessary. Serve hot.