Preheat the oven to 220° Celsius (425° Faranheit) as this dish needs a very high heat to work well. Place your roasting tin in the oven with a trivet or grill rack inside it to heat with the oven.
Take the piece of belly pork and score the skin with parallel strokes if this has not already been done by your butcher (it will be done by The Sausage Shed) and score through again at right angles, so that the skin is cut into squares. Don’t cut through the skin into the meat. Rub salt into the skin,ensuring that you get some into the scores you have made. Turn the meat over and lightly season with salt and pepper.
Carefully pull out the roasting tin and fill it with boiling water to just below the level of the trivet or grill rack. Place the meat on the rack, skin side uppermost, and cook for about 30 minutes. When you see the skin starting to bubble and form crackling, turn the oven down to 180° Celsius (350° Faranheit) and cook for another hour and a half. Keep the oven door shut during this time, so that the steam from the roasting tin tenderises the meat and keeps it moist, while the heat forms a delicious crispy crackling above.
Before serving, remove the meat from the oven and let it ‘rest’ for about ten minutes; this allows the meat fibres to relax making the it much more tender to eat. Carve and serve with vegetables, gravy and potatoes. You can vary this dish by cooking the meat on a trivet, over an empty roasting tin and after the first half hour, when you turn the heat down, put your potatoes and vegetables into the tray to roast. If you use this method, it’s a good idea to baste everything before serving.