Find a large casserole dish which is big enough to submerge the gammon, and fill it with water. Gently bring the gammon to the boil, then reduce to a gentle simmer.
Take out a meat thermometer, and cook until the probe temperature of the thickest part of the gammon is between 88-90°C.
Remove the casserole dish completely from the heat and allow to cool in the cooking liquid, ideally overnight.
When completely cooled, remove from pan and carefully remove the skin, leaving some on the hock if you prefer.
The fat should be set hard, so you can ‘criss-cross’ the fat with 1” deep cuts with a sharp knife.
Place in a roasting pan and cover the fat with a glaze of your choice.
Place in a moderate oven (or pizza oven!) for 30 minutes, removing from the oven every 10 minutes to baste the gammon with the juices from the pan.
The total cooking time will be between 4-8 hours depending on the size of the gammon.