directions

1. In a small bowl, mix the treacle, cider vinegar, paprika, cumin, mustard powder and chilli powder until smooth. Using a sharp knife, make deep slashes in the skin of the pork shoulder to cut through the skin and fat layer, but not the meat. Place the joint, skin-side down, in a large dish and rub the spice paste into the meat. Turn skin-side, cover tightly with cling film and put in the fridge for at least three hours.
2. Heat the oven to 150˚C/130˚C fan/gas mark 2. Transfer the pork, skin-side up, to a deep roasting tin, rub the salt onto the skin and pour 500ml of water into the bottom of the tin. Cover tightly with foil and roast in the oven for five hours.
3. Remove the foil, increase the oven temperature to 200˚C/180˚C fan/gas mark 6 and cook for a further 1½ hours or until the pork is very tender and the skin has turned to crispy crackling.
4. Once the pork is ready, take it out of the roasting tin, cover with foil and leave to rest. Pour the juices from the roasting tin into a jug and leave to separate. Pour off the fat layer and transfer the remaining juices to a large sauté pan. Simmer over a high heat, stirring, until reduced to a rich gravy.
5. Slice thick pieces of the tender pork to serve alongside mashed potatoes and glazed carrots, with the gravy poured over.