Oxtail stew

Clean a big ox tail thoroughly and cut it into big pieces.
Brown a mixture of lard and oil in pan, and add the tail. Add the chopped onion, garlic, cloves, salt and pepper, and after a short while pour the white wine on top and cover with its lid.
Cook for 15 minutes, then add the peeled tomatoes. Cook for another hour, then cover the pieces of tail with hot water, lower the flame and let it boil until the flesh comes off the bone.
Eliminate the strings from the white celery and boil it, then take some of the tail sauce and add the boiled celery, pinenuts, sultanas and sprinkle some grated dark bitter chocolate. Let it cook for 5 minutes and pour this sauce on the tail when you are ready to serve it (obviously hot).