I usually soak the gammon in water overnight, but ask your butcher if this is necessary, and, if you do, discard the soaking water before starting.
Place the gammon in a large saucepan, cover with water and add the carrot, onion, celery, bay leaf and the peppercorns. Bring to the boil and then turn down to a low simmer, covered, for 2 3/4 hours.
Preheat the oven to 180°C Gas Mark 4.
When the gammon is cooked, make the glaze by mixing all of the ingredients (except the cloves) together in a bowl.
Remove the gammon from its cooking water and drain well. Cut the rind and some of the fat off the gammon (leaving a thin layer of fat). Score the fat diagonally in a criss-cross pattern and then stud with the cloves all over.
Put the gammon joint in a roasting tin, brush over the glaze and bake in the preheated oven for about 25-30 minutes until stick and golden. Serve hot or cold.
Recipe courtesy of Lisa Faulkner