Fry the belly of pork quickly until brown in a pan with 50 g (2 oz) butter; remove and place on one side then fry the veal in the same fat until brown; remove and place with the belly of pork. Fry the liver very quickly in the same fat until coloured, replace the veal and pork and add the mushrooms, truffles, thyme, bayleaf, shallots and seasonings. Fry together for 2 minutes then turn out on to a tray. Deglaze the pan with the Madeira. Pound the fried ingredients very finely adding the remainder of the butter, the egg yolks one at a time, the reduced sauce and the deglazed Madeira. Pass through a fine sieve, place the mixture in a basin and work together until smooth, using a wooden spatula.