Bake potatoes at 425 degrees for 1 hour. Cut in half lengthwise, scoop out carefully into large mixing bowl. Add butter, milk, and egg and beat with electric mixer until smooth. Add cheese, chives, salt and pepper, and mix well. Heap back in shells and sprinkle with paprika.
Put on cookie sheet, freeze thoroughly, then put in plastic bags. When ready to use, thaw and bake at 350 degrees for 25 minutes.