Method
Preheat the oven to 190°C, gas mark 5. Butterfly the pork, ask your butcher to do this for you or simply cut through the underside of the meat horizontally, and roll out flat. Crush the fennel seeds and garlic. Strip the leaves from the rosemary stalks. Cut the lemon and squeeze the juice over the flattened pork. Sprinkle the fennel, garlic, rosemary and sea salt over the meat and roll. Tie with string at 2cm intervals to secure the joint. Rub with sea salt and place in an oven dish. Roast for 1½ hours, basting from time to time until crispy and golden. Check that the juices are running clear and allow to rest for 10 minutes before carving.