It is difficult to be specific about the size of the gammon you need: it depends how much you want left over. But I wouldn’t consider getting a joint weighing under 2kg. What you’re after is a joint of mild-cure gammon. I prefer to get my gammon from the butcher, but I have made more than respectable boiled ham from the vacuum-packed variety bought at the supermarket.
I don’t soak my gammon: I just cover it with cold water, bring it to the boil, throw all the water out and put the g