Cut the skin of the turkey along the backbone, separate the skin in one piece using the fingers. The skin is elastic and should come away easily.
Make fillets of the thickest turkey parts and cut them in strips. Remove the meat from the legs and wings, the breasts should be reserved. Mince the turkey meat (legs and wings) and mix with the pork and veal in a large bowl.
Season the minced meat with salt and ground black pepper, also sprinkle with the brandy and sherry, add the ham (jamón serrano) and belly of pork in strips. Add the chopped truffles and their juice too and leave marinate for 4 hours approximately together with the beaten eggs.
Of the large bowl remove the sliced truffles, the strips of ham and the belly pork, reserve them. Knead the filling by hand.
Spread out the turkey skin on the kitchen table, lay the fillets on top like the pages of a book and cover them with a layer of the minced meat and then with a layer of ham and belly of pork strips then breasts and a layer of truffles slices. Repeat until all ingredients have been used.
Place the skin with its filling on a napkin, roll it around and sew with large stitches, then tie it into a roll with uncolored string.
Into a large saucepan put the roll with the vegetables and the carcass and giblets of the turkey, pour over these the dry sherry. Also add the ham bones, eggshells and the gelatin. Season them with salt and black pepper. Pour 3 liters of cold water and boil for 3 hours.
When the roll is cooked remove it from the saucepan. Once the roll is drained remove the cloth in which it is wrapped. Place the roll on a dish and place a chopping board on top, press for 12 hours and put into the refrigerator.
Cut the roll into slices 1 cm. thick, serve with puree of apples. The dish can be decorated with plums and slices of fresh pineapples and orange, also you can use maraschino cherries.