Butterflied Leg of Lamb Over Charcoal

Method

1. Even out the thickness

   A butterflied leg is naturally uneven. Cut into the thickest sections and open them out like a book, and score the thinner areas less. The flatter it is, the more of it lands at the same doneness. Some unevenness is useful though, since it gives you rare and medium in one piece.

2. Marinate overnight

   Mix everything and work it into both sides and into every cut. Twelve hours in the fridge. Lamb takes garlic and rosemary better than almost any other meat, so be generous.

3. Bring it to room temperature

   An hour out of the fridge before cooking. A cold four pound slab will char on the outside long before the middle is anywhere near ready.

4. Indirect at 190°C (375°F)

   Bank the coals and put the lamb fat side up on the cool side, lid on. Around 30 minutes, until the thickest part reads about 45°C (115°F). Wipe off any loose marinade solids first or they will burn.

5. Sear over the coals

   Move it directly over the bank. Four to five minutes a side, turning when it is deeply coloured and the fat has crisped. Expect flare-ups from the fat and oil, and move the meat rather than letting flames sit on it.

6. Pull at 55°C (130°F)

   Probe the thickest section. 55°C (130°F) gives medium rare there, which means the thinner sections come out medium, which is usually what a table of eight actually wants.

7. Rest 15 minutes, slice thin

   A large piece needs a real rest. Slice thinly against the grain, which runs in different directions across a butterflied leg, so check as you go. Serve the resting juices over the top.

Notes worth knowing

• Ask the butcher to butterfly it and to trim the heaviest fat and gristle seams. It is a fiddly job at home.
• Lamb fat solidifies unpleasantly as it cools, so serve this hot and on warm plates.
• Leftovers are excellent cold in flatbread with yoghurt, cucumber and lemon.

Common questions

Bone-in or butterflied?

Bone-in gives you a more impressive roast and juicier meat, but takes two to three hours and cooks unevenly around the bone. Butterflied is faster, easier to control, and gives far more charred surface, which is the best part.

What temperature should lamb be?

50°C (125°F) rare, 55°C (130°F) to 55°C (135°F) medium rare, 60°C (140°F) medium. Past 65°C (145°F) leg of lamb gets noticeably dry and the flavour turns muttony.