In a large saucepan melt butter. Saute garlic in butter for 3-4 minutes. Stir in broth and tortellini and bring to a boil. Cover, reduce heat, and simmer for about 5 minutes.
Add remaining ingredients, except grated Parmesan cheese. Simmer 10-15 minutes,stirring occasionally to break up frozen spinach. When soup is thoroughly heated check for seasonings and add salt pepper or garlic as desired. Serve in bowls with grated Parmesan on top.