I would boil it first then roast but you don't have to do that. It does remove a lot of salt though
What you put on it is up to you, I generally go for honey
Do you have a slow cooker? Gammon in that is gorgeous!
Are you doing it today?
I usually soak mine for the night before I want it, changing the water a couple of times, then I roast it on a low heat or quite a few hours, it goes nice and shreddy.