Place the gammon joint in a roasting tin with the carrots & onion (and sliced apple if using)
Pour over the cider and add enough water so that the joint is covered.
Put in a preheated oven gas 7 / 220º for half an hour
Turn down to gas 5 / 190º for a further 2 hours.
Turn the gammon half way through cooking.
When cooked, allow to rest for 10 15mins before serving.