Preheat oven to 350 degrees. Mix together egg, milk, shredded cheese, peppers and onion. Pour into 12 muffin cups. Bake for 20 minutes. Remove from pan and allow to cool completely. Wrap each "egg" in plasic wrap and freeze. When ready to eat, set broiler on low and put in split English muffins. Microwave "egg" for 20 seconds. Put on engligh muffin under broiler and top with 1/2 slice of copper cheese. Broil for 5 minutes. Remove and eat, or wrap in foil for transport.