Put the gammon in a large pan and cover with water. Bring to the boil and skim any foam from the surface, then reduce to a simmer, cover and cook for 2 hrs. Leave to cool in the liquid in the pan for 30 mins.

Meanwhile, make the glaze. Tip all the ingredients into a pan and bring to the boil. Reduce to a simmer and bubble for 10-12 mins, or until just syrupy. Drain the gammon (you can reserve the liquid for stock). The gammon and glaze can be prepared and chilled up to one day ahead.

Heat the oven to 200C/180C fan/gas 6. Sit the gammon on a board and, using a sharp knife, cut away the skin, making sure you leave a good layer of fat. Score lines all over the fat. Transfer to a roasting tin and roast for 10 mins, then pour over some glaze. Continue to roast, basting with more glaze every 5-10 mins, until the gammon is sticky, about 40 mins. Don’t worry if the ends get a little dark, as this adds flavour.

Remove from the oven and rest for 15 mins. Carve and serve.