Place cooked beef in a large resealable freezer bag. Add the frozen hash browns, minced onions, dry onion soup mix, beef broth, and pepper.
Put the shredded cheese in a medium freezer bag. Seal. Staple the bags together above the seal and freeze.
Bake at 350° for one hour, topping with grated cheese for the last 10 minutes.
Cook in the slow cooker on low for 2-4 hours, topping with cheese for the last 20 minutes.