Explainers

How to butterfly lamb leg

Knowing your way around a lamb leg opens up serious grilling potential. Butcher Richard Gunner demonstrates how it's done.

By David Matthews
How to butterfly lamb leg

Boning and butterflying a lamb leg turns a wintry cut into one primed for barbecuing. Not only does a butterflied leg cook relatively quickly, it marinates well and has the benefit of picking up char from the grill.

"It's one of the easier and more satisfying home butchery skills to have a go at if you use the shank end," says Richard Gunner of Richard Gunner's Fine Meats and Feast! Fine Foods in South Australia, referring to the lower half of the leg that doesn't include the difficult-to-remove "aitch" bone. While you may come across butterflied legs, "bone-in is cheaper, so you can buy better quality", says Gunner.

Freeze the bone so come roasting season you can pop it in the tray to enrich the pan juices.

WHY YOU SHOULD BUTTERFLY LAMB

Butterflying not only opens a lamb leg out so the meat cooks evenly to the same degree throughout, it also maximises the surface area, which helps when you're adding flavourings. "Don't be afraid to put a few slashes in the leg," says Gunner. "This makes sure the muscle bundles won't pull tight and curl up on the grill, and also helps any spices or marinades you use to penetrate the meat – I love either Greek-style with fragrant herbs, lemon, garlic and olive oil, or North African flavours like harissa or ras el hanout."

TOOLKIT

While you can use a paring knife, a boning knife – typically a short, curved knife with a rigid blade – is designed for cutting through meat and joints, and up against bone. "The right knife will make your job much easier," says Gunner. That might be a highly curved Tojiro knife, or a more classic Mundial or Wüsthof ($155, $54 and $144 from Peter's of Kensington, below, from left).

The best knives for butterflying a leg of lamb
The best knives for butterflying a leg of lamb

HOW TO BUTTERFLY LAMB STEP-BY-STEP

1 With the leg fat-side down and the thick end facing you, feel along the leg to locate the knee joint. The first cut is from the knee to the exposed bone at the top of the leg. Make a small cut where you judge the bone to be, then feel with your fingers to check you're on the right line, and continue the cut along the bone towards you.

Step 1: find the bone
Step 1: find the bone

2 You can now pull the meat apart a little to reveal the bone. Cut along the sides of the bone to expose it more and more, aiming to leave as little meat on the bone as possible. "Take your time and mostly use the tip of your knife," says Gunner. And take care not to cut towards your fingers.

Step 2: cut around the bone
Step 2: cut around the bone

3 With the bone exposed, slip the tip of the knife under it from the side and then cut up along the bone to free it from the flesh at one end. Now cut down the bone the other way, scraping down to the joint. The whole bone should now be exposed down to the knee.

4 Cut around the knuckle to expose it (turning the leg up on its side helps). Taking your time, work around the joint, then lay the leg flat again and cut along the line of the bone to expose it, before cutting along the sides with the tip of your knife as you did earlier. (Once you reach the knuckle, it's also possible to follow the seam and free the lamb shank with the bone in. You could then freeze this and wait until you have a few stored for a braise. Just cut through the joint to remove the top bone before freezing.)

5 Slide the knife under the bone and, again removing as little flesh as possible, free it from the meat completely.

Step 5: remove the bone
Step 5: remove the bone

6 Lay the leg flat and trim off any pieces of bone, gristle and large pieces of fat. "Your aim now is to make the leg the same thickness all over," says Gunner. "This makes all the difference when you cook it." With a smooth motion, slice horizontally halfway through the thicker pieces of meat, opening them up like a book and folding out until the thickness is consistent.

Step 6: even things out
Step 6: even things out

7 Make a few cuts in the surface of the meat to help it cook more quickly and evenly.

Step 7: prepare for seasoning and grilling
Step 7: prepare for seasoning and grilling

Now you're ready to cook barbecued lamb leg with saltbush rub or butterflied lamb leg with smoky eggplant. Fire up the barbecue.