Place the joint in an roasting tray and cover with foil to retain the moisture and bake it in the pre-heated oven at 180°C (fan 160°C), gas mark 3 for 20 minutes per 500g plus an extra 20 minutes. Alternatively, you could braise it on a bed of stock, beans and other vegetables.  

To boil your gammon, place it in a pan and cover with cold water, add cloves, black peppercorns or bay leaves to flavour if required. Bring the water to the boil, when the water boils, reduce the heat, cover and simmer for 20 minutes per 500g plus 20 minutes or until thoroughly cooked