Pre-heat oven time gas mark 7 or electric equivalent. Normally about 220C or 180C on my Circotherm

If not already done by butcher, score the skin but do not cut into the meat. Rub sea salt into the cuts and drizzle olive oil over the skin. Turn joint over and lightly season other side. Return to skin-side up and sprinkle on the thyme and rosemary.

Put a little olive oil in your roasting dish, roll the onion halves and garlic cloves in the oil to cover thoroughly and place towards the centre of the dish. Place the joint skin-side up on top of the vegetables and put into the pre-heated oven.

After 30 minutes check that the crackling has turned golden-brown. Carefully pour the wine into the roasting dish so that it goes around the meat but not over it. Lower the temperature to gas mark 4 (electric equivalent about 180C, Circotherm 160C) and cook for a further 30 minutes per 500g of meat weight.

Check that meat is properly cooked, then remove from oven (leaving the onions and garlic in the roasting dish), cover with foil and allow to rest for 20-25 minutes.

Use the juices and vegetables to make gravy. Carve the meat and serve with roast potatoes plus vegetables of your choice. Also an apple or other sauce if wished.