Just found that I had already typed the recipe on to my computer. It's from Nigella's book - NIGELLA BITES
HAM IN COCA-COLA
2kg mild-cure gammon
1 onion, peeled and cut in half
2-litre bottle of Coca-cola (not diet)
For the glaze:
handful of cloves
1 heaped teaspoon of black treacle
2 teaspoons of English mustard powder
2 tablespoons demerara sugar
I find now that mild-cure gammon doesn't need soaking, but if you don't know that you're dealing with a salty piece, then put it in a pan covered with cold water, bring to the boil, then tip into a colander in the sink and start from here; otherwise, put the gammon in a pan, skin-side down if it fits like that, add the onion, then pour over the Coke. Bring to the boil, reduce to a good skimmer, put the lid on, though not too tightly, and cook for just under 2� hours. If your joint is larger or smaller, work out timing by reckoning on an hour per kilo, remembering that it's going to get a quick blast in the oven later. But do take into account that if the gammon's been in the fridge right up to the moment you cook it, you will have to give it a good 15 minutes or so extra so that the interior is properly cooked.
Meanwhile, preheat the oven to 240C/gas mark 9.