1 Leg of lamb weighing 1 1/2 to 2 kg
6 cloves of garlic, peeled and cut into 4 slices lengthwise
2 to 3 sprigs of rosemary
6 tbsp olive oil
2 tbsp wholegrain mustard
Freshly ground black pepper
1 roasting tray and rack
Set the temperature at 250ºC, that's 475ºF or gas mark 9.
Rub the leg of lamb with the mustard and generously season with salt and pepper.
Make incisions in the lamb with a small knife and insert the garlic and rosemary.
Place the leg of lamb onto a roasting rack above the tray and drizzle over the olive oil.
Put the roasting tray in the oven and cook for 1 hour.
After about 30 minutes, lower the temperature to 200ºC (460ºF, gas mark 6) and continue cooking for the remaining 30 minutes.
After the cooking time, check that the lamb is ready.
Insert a knife into the thickest part of the leg. The cooked meat should be of a pinkish colour.
Remove it from the oven and leave to rest for 15 minutes.
Carve the leg of lamb and serve with roast potatoes, a selection of vegetables, gravy and mint sauce.