Photograph: Emma Lee
Put the gammon in a large pan, add the other gammon ingredients and top up with cold water to cover the gammon by 2cm. Bring to the boil, skimming off and discarding any impurities as they rise. Reduce the heat and simmer very gently for 1 hour 20 minutes. Remove from the heat and leave to cool in the liquid for 1 hour.
Preheat the oven to 220°C, fan 200°C, gas 7. Remove the gammon from the stock and transfer to a board. Remove the skin; score the fat into diamonds and stud the fat with the cloves.
Mix together the sugar, honey, mustard and ground spices. Transfer the gammon to a foil-lined tin and brush the fat with half of the glaze. Roast in the oven for 20 minutes, spooning the remaining glaze over the top halfway through.
Get ahead: if serving cold, prepare the gammon up to 3 days ahead; chill. If serving hot, prepare 3 hours before serving.