Remove the bone from the leg of lamb, then to butterfly, place the lamb skin side down on a board, slice through the meat holding the knife parallel to the board to give you a flap of meat which you can open out like a book.
Repeat on the other side, the idea is to produce a flattish piece of meat roughly the same thickness throughout.
Place the meat into a glass or ceramic dish, whisk together the remaining ingredients and pour over the meat turning to coat it well, allow to marinade in the fridge for a couple of hours or even overnight.
Remove from marinade, season with sea salt and black pepper and place skin side down first and cook for about 10 minutes per side for medium. Allow to stand for about 10 minutes and slice to serve.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home.