Prepare Ahead Mashed Potatoes
["potatoes", "warm milk", "butter", "1 egg, separated"]
["For \"Mashies\" that stay smooth, mash the potatoes with warm milk, butter and an egg yolk.", "Whip an egg white and fold it into the potatoes.", "Place in a buttered casserole and dot with more butter.", "Cover and refrigerate until ready to use."]
["potatoes", "warm milk", "butter", "egg"]