Remove the skin from the kidneys, cut in half lengthways and sauté quickly in hot butter tossing them over quickly. Drain well.
Arrange in a circle each on a Croûton of bread cut to the shape of a cockscomb and fried in clarified butter. Fill the centre with glazed button onions, chipolata sausages fried in butter and small cooked mushrooms.
Deglaze the pan with Madeira, reduce, add the necessary amount of Sauce Demi-glace and shake in