A favourite way of cooking ham from the deep South in the States- it tastes much better than it sounds. Its from ” Nigella Bites ” by Nigella Lawson though she has an earlier version in ” How to Eat”. The stock left over from cooking the ham makes a good base for a black bean soup . Mild -cure gammon should not need soaking, but if you have a salty piece put it into a pan covered with cold water, bring to a boil then drain in a colander.
Put the gammon in a large pan, skin side down then add the onions and pour over the Coke.
Bring to the boil, reduce to a good simmer, partially cover and cook for just under 2 1/2 hours. If your joint is smaller work on the basis of an hour per kilo. Meanwhile preheat the oven to 240 C, 220 Fan Gas Mark 9.
When the ham is done remove from the pan, reserving the cooking liquid and let it cool a little. You can prepare everything up to this point some time in advance if wished.
Remove the skin leaving a thin layer of fat. Score the fat with a sharp knife to make large diamond shapes. Stud each diamond with a clove then carefully spread the treacle over the skin.
Gently pat the mustard and sugar on to the sticky fat. Put into a foil lined roasting tin and cook for about 10 minutes until the glaze is browned and bubbly. If the ham has cooled it will need 30-40 minutes at 180 C, 160 Fan Gas 4. Increase the heat towards the end if you need to.