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

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

Stir in the diced potatoes and chicken broth. Bring to a boil, then reduce heat and simmer for 20 minutes, or until the potatoes are tender.

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

Serve hot, garnished with additional cheese if desired.