Soaked the smoked gammon overnight or a good 10 hours, changing the water a couple of time. This is to remove the saltiness.
Place the gammon into a big pot and cover with the ginger beer, the herbs, a couple tablespoon of whiskey and onions too except for the Seville Orange Marmalade
Boiling time - 15 minutes for 500g + another 10 minutes after. My gammon was 2.5 kg thereabouts so I boiled for 90 minutes + 10 minutes. (100 minutes total)
Leave the gammon in the ginger beer stock till it is cool to touch. Remove the gammon and and place on your roasting pan.
Line your roasting pan with the onions and some stock to ensure the juiciness.
Use a sharp knife and remove the skin of the gammon and score the fat.
Mix the Seville Orange Marmalade jam with a tablespoon of whiskey and smeared the top of the gammon.
Place into a 180 C fan assisted oven for 25 to 30 minutes until it is golden. Remove from oven and then drizzle again with another tablespoon of whiskey.