1. Peel the garlic and red onions, and halve and deseed the Scotch bonnets, then place in a food processor – wash your hands thoroughly afterwards. Add the chives, sugar, rum, vinegar, all the spices and the salt. Pull off and discard the bay stalks, then add the leaves to the processor. Strip in the thyme leaves and blitz until very finely chopped.
2. Place the ham on a board and trim off the outer layer of skin, leaving a 1cm layer of fat behind. Score the fat all over in a criss-cross pattern, making sure you don’t cut down into the meat itself. Transfer the ham to a roasting tray and pour over the marinade. Rub it all over the meat, getting into all the nooks and crannies, then cover with clingfilm and place in the fridge to marinate for at least 2 hours, but preferably overnight.
3. When you’re ready to cook, preheat the oven to 180ºC/350ºF/gas 4 and leave the ham to come up to room temperature. Cover the tray with tin foil and reheat according to pack instructions. Around 40 minutes before the time’s up, remove the foil and pour over the rum. Add the marmalade and orange juice to the tray and mix together with the pan juices. Brush the glaze all over the ham and return to the oven for the remaining time, brushing and spooning the juices and rub over the top every 5 to 10 minutes until dark, stick and gnarly.
Once glazed to perfection, remove to a board to rest for 30 minutes before carving into nice thick slices. Pour the cooking juices into a jug, skimming away the fat – it’ll make an epic spicy gravy to drizzle over at the end, if you like. Serve with a fresh, crunchy salad and some Spiced peach chutney.
Jamie's Tip: Using a herb brush to baste the ham will infuse it with lovely flavour. Tie a bunch of woody herbs together at the stalk-end to create a brush, then bruise the leafy end by lightly bashing it with the bottom of a pan – this will release the oils and help amplify the flavour.