One quart of milk, one slice of onion, one slice of carrot, one blade of mace, two tablespoonfuls of butter, two tablespoonfuls of flour, three heaping tablespoonfuls of grated Parmesan cheese or three-fourths cup of American cheese, yolks of two eggs, salt and pepper. Directions: Put the milk on in the double boiler with the carrot, onion and mace; rub butter and flour together; when the milk has reached boiling point remove the vegetables and add the butter and flour; stir constantly until it thickens; add the cheese and stir until melted, then take it from the fire; add beaten yolks of the eggs, salt and pepper. Serve at once. This soup cannot be heated over.