The beauty of this technique is that the meat can be cooked in a quarter of the time it takes to roast a whole leg of lamb. Here barbecuing is shown, but the lamb can also be grilled. For the technique of butterflying.
Rub seasonings and olive oil over the lamb. Place, meat-side down, on the oiled rack of a preheated barbecue.
Cook for 20-30 minutes, turning once, until the outside is charred and the meat is tender when pierced.
Put the lamb on a board, cover loosely with foil and let rest 10 minutes. Carve crosswise into slices.