In a medium/large size pot, add the sausage. Cook over medium heat until browned. Once sausage is cooked through, use a slotted spoon and transfer the meat to a paper towel lined plate.
Add the onion and carrots to the pan. Saute until the vegetables are tender, about 4-5 minutes. Add the minced garlic, stir frequently, cooking for 1 minute more. Whisk in the flour. Cook for 1 minute, whisking constantly. Slowly add the chicken stock. Whisk to combine. Bring the mixture to a boil. When it reaches a boil, reduce heat to low, and cover. Simmer for 5 minutes.
Add the cheese tortellini, salt, Italian seasoning, black pepper, spinach, and half and half. Cook for 4-5 minutes or until the cheese tortellini is warm. Serve immediately.