Adjust oven rack to one below the middle and preheat the oven to 160°C.
Remove the elasticised ‘net’ from the gammon. Place meat on a bed of onions in a heavy based ovenproof saucepan or oval roaster with lid.
Add bay leaves and peppercorns. Dissolve Stock Powder in water together with sugar. Pour over the meat.
Cover with lid and bake for 2 ½ hours. Turn off the oven and leave gammon to cool in the liquid.
Set the oven temperature to 190°C.
Use a small, sharp knife to peel away the skin, leaving the fat layer behind. Slice into the fat layer to form a diamond pattern. Push a clove into the middle of each diamond. Spread the marmalade over the fat layer.
Bake until the marmalade layer turns caramel brown.
Serve warm or at room temperature, thinly sliced.

Mandarin  or Orange Garnish

Slice the mandarins, skin on, into 3 mm thick slices. Lay out on a baking paper lined baking tray. Brush generously with marmalade. Bake at 190°C until nicely browned.

Presentation

Push a carving fork deeply into the thinner end of the gammon. Garnish with a bouquet of fresh bay leaves or thyme. Slice gammon thinly and serve hot or at room temperature.
The marmalade mandarins are served on the side.