Method Sweet maple syrup contrasts perfectly with the rich gammon. Remember to save some meat for the next day's pie! Preheat the oven to 190°C/fan 170°C/Gas 5. Remove the packaging, apart from the netting, and rinse the joint. Dry with kitchen paper. Put a long piece of foil on a large baking tray and place another at right angles across the tray. Rub with oil. Sit the gammon in the centre and wrap the foil loosley over it, leaving space for air to circulate. Calculate how long the gammon will take to cook (see preparation/cooking time, above), then roast the joint in the middle of the oven. Thirty minutes before the end of the cooking time, remove the gammon from the oven. Using a sharp knife, remove the netting and skin, leaving the fat behind. Score the fat into a diamond pattern, spread a little of the mustard all over, then top with the syrup or marmalade and carefully cover with the sugar. Push a clove into the middle of each diamond, if using. Return to the oven for 30 minutes or until the gammon is golden all over. To serve warm, cover and leave to rest for about 20 minutes before carving.