Roast pork with apples

• half leg of pork, fillet end 1.5-1.8 kg (3-4 lb) in weight, with the skin well-scored by the butcher

Heat the oven to 190°G, 375°F, Gas Mark 5. Put the pork on a rack in a large roasting tin and rub it all over with oil. Place it in the middle of the oven and roast for 35 minutes per 450 g (1 lb), basting frequently. Half an hour before the end, add the cider to the basting juices in the tin; if the crackling is not quite hard and crisp when tapped with a wooden spoon, turn up the heat to 220°