Add the broth to the slow cooker and whisk in the flour until dissolved. Add the spices, onion, garlic, tomatoes, tomato paste and stir until incorporated. Cook on LOW for 4-5 hours or on HIGH for 2-3 hours. Add the frozen cheese tortellini and cook on HIGH for another 15-20 minutes or until the tortellini are done. Add the shredded Cheddar cheese, spinach, cream, cream cheese and and stir until the cheese is melted, then continue to cook for another 5 minutes or until the spinach is wilted. Add salt and pepper to taste.
Serve sprinkled with some freshly grated Parmesan cheese.