In a 4-qt. slow cooker, combine the first 9 ingredients. Cover and cook on low for 6-7 hours or until heated through. Stir in spinach. Cover and cook for 15 minutes or until spinach is wilted. Sprinkle with cheese. Freeze option: Before adding cheese, cool soup. Freeze soup in freezer containers. To use, partially thaw in refrigerator overnight. Heat through in a saucepan, stirring occasionally; add broth or water if necessary. Sprinkle each serving with cheese.