Preheat oven to 180 degrees C.
Carefully remove the ham skin, sliding your fingers underneath it and peeling off. Try to leave the fat intact as this will be glazed over and it keeps the ham deliciously moist. Leave the skin on the hock area.
Place the ham, cut side up in a large roasting tray and rub the jam or marmalade all over. You can, if desired, score the fat into diamond shapes and press in cloves but generally leave it plain and serve simply glazed and rustic-like.
Bake for an hour, watching it doesn't get too browned on the glaze. Wrap the hock end in ribbon, tucking in the leaves as garnish. Serve with mustards and cranberry sauce.