Which is a very different thing from souffle potatoes. Beat a cupful of mashed potato to a cream, add the yolks of three well-beaten eggs and a tablespoonful of melted butter, season with pepper and salt and a dash of onion-juice; whip in by degrees a cupful of rich milk, lastly the frothed whites of the eggs. Pour into a buttered bake-dish and cook, covered, until it rises well, then brown. Serve at once. It soon falls and settles.