Preheat the oven to gas mark 7 / 220º
Place the pork in a roasting tin. Score the top with a sharp knife. Rub in the oil, salt & pepper.
Crush the Garlic gloves and rub over the top and then place in the tin along with the carrots, onions & thyme.
Place in the oven uncovered for about half an hour.
Turn the oven down to Gas mark 3/ 140°. Cover the pork with tin foil and continue to roast for about 4 - 4½hrs.