This grilled butterflied leg of lamb is spectacular. Leg of lamb is a premium cut, so you want to make it right. For a successful cook every time, butterfly it. Butterflying allows the lamb leg to lie flat on the grates for even cooking. You can get your butcher to remove the bone and butterfly the leg, but doing it yourself is easy and economical. Once prepped, the lamb spends a few hours in a delicious marinade loaded with Mediterranean flavours before grilling to a perfect medium-rare.