Remove the fat and skin from the kidneys and cut in very thin slices. Put a little butter in a deep frying pan and, when hot, put in the kidneys, season with salt and pepper, sprinkle with the finely chopped onion and parsley, and add the white wine. Cook for a few minutes—3 or 4 at the most—on a fairly quick fire. Now mix in the Espagnole sauce, the cooked peas, sliced truffle and the cooked mushrooms. Cook all for a few minutes longer till the kidneys are done. Place on a hot dish and garnish with vegetables, the fried ham and slices or quarters of hard-boiled egg.