In a large soup pot, cook the Italian sausage over medium heat, breaking it up as it cooks until fully browned. Transfer sausage to a paper towel-lined plate.

Add the chopped onion and celery to the pot. Cook for 4-5 minutes until softened. Stir in minced garlic and cook for another minute.

Sprinkle the flour over the sautéed vegetables and stir for about a minute. Slowly pour in the chicken broth while stirring to prevent lumps.

Add the diced tomatoes with juices and Italian seasoning to the pot. Return the cooked sausage and bring to a gentle boil.

Reduce heat and add tortellini. Simmer for about 5 minutes until pasta is cooked and tender.

Stir in the heavy cream until well combined. Add spinach and let it wilt for 2-3 minutes.

Season with salt and pepper to taste. Serve hot, optionally topped with shaved parmesan.