Soak the gammon in cold water in the fridge for at least two hours.
Simmer gammon with cider, juice, apples, and spices for 1.25 hours.
Preheat the oven to 200°C.
Transfer gammon to a roasting tin and reserve the cooking liquid.
Remove the rind and score the remaining fat into diamonds.
Cook a ladle of stock with sugar and chilli until thick, then glaze and roast for 15 minutes.
Boil the remaining cooking liquid until reduced to 500ml.
Strain the liquid through a sieve, pressing the apple flesh into the sauce.
Thicken the sauce with cornflour paste and serve over sliced gammon.