Rinse the tongue and then soak it in plenty of cold water for at least 12 hours. Change the water once or more during this time. Next day choose a heavy-based saucepan or flameproof casserole that will hold the tongue snugly. Put the tongue into it, cover with cold water, bring to the boil and skim. Taste the water; if it is very salty, tip it away, add fresh water and bring to the boil again. Add the chopped vegetables, peppercorns and a bouquet of bay, parsley and rosemary. Cover tightly and cook very gently on top of the stove or in an oven heated to 300 F (150 C) gas mark 2 for about 4 hours until the tongue is so tender that a skewer will go through the root end like butter. Lower the temperature as necessary; the meat will be best if barely a bubble breaks the surface of the liquid as it cooks. Skin the cooked tongue while it is still hot. Then cut away the fat and gristle from the end and remove all small bones if the butcher has not already done this. Skim off all the fat from the cooking liquor and save it for the sauce and for soups.
If The Tongue Is To Be Served Hot, carve it in thin slices while it is still hot and arrange it prettily, overlapping slices like tiles, on a large warmed serving dish. Pour some good hot sauce over it, cover the dish with foil and place in the oven for about 10 minutes to heat through. The spiced Kumquat Sauce recipe is one of my favourites and I like to serve extra in a sauce boat.
If The Tongue Is To Be Served Cold, mould and glaze it while still warm. Curl the tongue to make it fit a small round container with straight sides. Traditional tongue-presses usually measure about 5-6 inches in diameter; a cake tin or souffle dish of similar size will do just as well.
To glaze, melt 2 teaspoons gelatine powder in 1 tablespoon water, then blend in a scant 1/2 pint tongue cooking liquor (seasoned and reduced as necessary for good flavour), and give it a little oomph with 1-2 tablespoons Madeira. Pour over the tongue as much of the liquid jelly as is needed to fill gaps. Press the tongue down with a saucer or plate which fits just inside the tin, weight it down heavily and leave overnight in a cold larder until meat and jelly are set. Chill any left-over jelly separately so that it can be diced and used to garnish the tongue when it is served.
Unmould the tongue on to a flat dish for serving. Decorate it and accompany it with a fine sauce such as a classic Cumberland sauce or Piquant Parsley and Caper Sauce.