Points to remember
- Score the skin with a sharp knife to help the fat escape during cooking, but don't cut all the way into the meat.
- Pat skin dry then rub with salt and oil to help the fat render and the skin to puff and crisp.
- Weigh joint and roast the meat for 25 mins at 240C/fan 220C, then turn the oven down to 190C/fan 170C and roast for 25 mins per 450g/1lb.
- Rest the meat for 10-15 mins before carving.
If you find that the crackling isn't as crispy as you'd like near the end of the roasting time, turn the heat up and cook for a further 10-15 mins. Be careful not to overcook the meat though, as it will become dry.