Preheat oven to 180C degrees
Place your gammon in a large pot and wash with cold running water
Drain the water and then fill the pan up with fresh cold water
Add some black peppercorns and half the thyme
Place on the hob on a medium heat and place the lid on, bring to the boil and gently simmer for 2 hours, or until the meat is tender
Remove from the pan and let cool for 5 minutes, retaining half of the stock
Put the maple syrup, brown sugar and thyme in a small pot and gently dissolve the sugar
With a small knife remove the skin making sure to leave a covering of fat
Score the fat in a criss-cross fashion
Place the gammon in a roasting tray with the remaining stock
Pour over half the glaze and roast in the oven for 20 minutes
Baste with some of the stock and then pour over the remaining glaze and continue to cook until the ham is fully glazed