Heat a Dutch oven or heavy pot over medium-high heat. Add the sausage, carrots, and onion. Cook for 8 to 10 minutes, stirring often, until the sausage is cooked through and the vegetables are soft.

Stir in the garlic and cook for about 30 seconds, keeping it moving to avoid burning.

Stir in the flour until everything is well coated. Then add the Italian seasoning, mustard powder, salt, black pepper, and red pepper flakes, stirring well to spread the seasonings evenly.

Pour in the chicken stock and simmer for 1 to 2 minutes, stirring gently until the soup starts to thicken.

Add the heavy cream and frozen tortellini, bringing the soup to a boil, then lowering the heat to a simmer until the tortellini is tender.

Stir in the spinach and parmesan cheese, simmering on low for 1 to 2 minutes, until the spinach wilts and the cheese melts.