01 -  Combine beef stew meat, sliced onion, minced garlic, mushrooms, beef broth, Worcestershire sauce, paprika, salt, and black pepper in a large freezer-safe bag. Seal and lay flat for even freezing. 
 02 -  Store the sealed bag in the freezer until ready to use. 
 03 -  Thaw the contents of the freezer bag overnight in the refrigerator. Pour mixture into a slow cooker and cover. Cook on low for 6 to 7 hours until the beef is tender. 
 04 -  Stir in sour cream just before serving. Serve hot, preferably over cooked egg noodles or mashed potatoes.