Select six medium-sized potatoes and bake, following recipe for Baked Potatoes. Remove from oven, cut slice from side of each, and scoop out inside. Mash, add two tablespoons butter, salt, pepper, and three tablespoons hot milk; then add whites two eggs well beaten. Refill skins, and bake five to eight minutes in very hot oven. Potatoes may be sprinkled with grated cheese before putting in oven.