Heat a quart of milk; toast slices of bread, butter them and dip each into the milk a second. Lay in a deep serving dish. Now add a tablespoon of butter and a pinch of salt to the hot milk. Beat the yolk of an egg, adding gradually a small tablespoon of flour and two tablespoons of cold milk. Stir into the boiling milk and cook until creamy, then pour it over and around the toast and serve immediately. May be served with poached eggs, too.