Soak the tongues well in salt water for 1 hr., then blanch and dry them. Melt the fat in a stew-pan and add the roughly sliced vegetables. Put on a tightly fitting lid and toss for 10 min. over a very low heat. Lay the tongues on top, add the bouquet garni, peppercorns and enough stock almost to cover the vegetables. Place the bacon on top of the tongues. Cover with greased greaseproof paper, and the lid, and cook gently for about 2 hr. or until the tongues are tender. When ready, skin the tongues, cut in halves lengthwise and brush with warm glaze. Place on a greased paper in a baking-tin and put in a warm oven for a few minutes to reheat.
Serve on a bed of mashed potatoes or spinach purée. Serve with brown sauce.