How to Cook a Bone-in Leg of Lamb

Roast Leg of Lamb

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Start to Finish: 2 hours Servings: 4 to 6 Difficulty Level: Intermediate

Lamb is a regal preparation at its simplest, but a proper leg of lamb with the shank bone attached is kingly. The shank bone, or the portion of leg extending below the knee, doesn't influence cooking technique or taste, but it isn't superfluous, either -- it's a worthwhile embellishment rooted in minimalism. New Zealand leg of lamb differs from American leg of lamb in size; the latter cut weighs as much 15 pounds, whereas the former averages between 5 and 6 pounds, but the cooking technique is the same for both.


  • 1 tablespoon lemon juice
  • 1/4 cup olive oil
  • Kosher salt, to taste
  • Black pepper, to taste
  • Fresh herbs, to taste
  • Instant-read digital thermometer
  • Foil
  • Stock (optional)
  • Butter


Pat the leg of lamb dry with paper towels and set it fat-side-up on a kitchen towel. A kitchen towel is a must for stability.

Trim 1 1/2 to 2 inches of meat and sinew from the shank using a paring knife or boning knife. Scrape the bone clean and wipe it with lemon juice to remove any residual blood.

Trim the fat cap, known as the fell, to 1/4 to 1/3 inch thick if you bought the lamb untrimmed.

Score the fell in a 1/2-inch crosshatch pattern. Scoring helps the fat render and baste the lamb during cooking.

Rub a coating of olive oil into the leg of lamb. Massage the oil into the folds and creases of the meat and scored fat very thoroughly.

Season the lamb liberally with kosher salt and freshly ground black pepper.

Tie the leg of lamb crosswise at 1 1/2- to 2-inch intervals using kitchen twine. Place the leg of lamb fat-side-up on a wire rack set inside a deep roasting pan.

Sear, Roast and Rest

Heat the broiler for 5 minutes. Adjust the oven rack to 4 to 6 inches below the broiler. Place the lamb in the oven.

Sear the lamb until it browns, about 5 minutes. Turn the leg of lamb over in the pan. Sear the lamb for another 5 minutes. Take the lamb out of the oven.

Set the oven to 350 degrees Fahrenheit. If you have an oven-safe digital thermometer, insert it in the thickest portion of the lamb without touching the bone.

Cover the leg of lamb loosely with foil if you used fresh herbs. Return the lamb to the oven.

Roast the lamb for 1 hour, and then check the internal temperature. A 5-pound leg of lamb should read about 125 F, or medium-rare, after 1 hour of roasting. For medium leg of lamb, continue roasting until it reaches 135 F, about 15 minutes.

Transfer the lamb to a carving board or platter after you take it from the oven. Loosely cover the lamb with foil and let it stand for 10 minutes before cutting the twine and slicing it.

Spontaneous Sauce

Remove the rack from the roasting pan and spoon off all but 1 to 2 tablespoons of fat. Place the pan across two burners on the stove and set them to medium.

Deglaze the pan using 1/2 cup of water or stock.

Simmer the water or stock until it reduces by half. Stir in 1 to 2 tablespoons of butter, and serve.

Cooking Tips

Dress the lamb with an herb paste after you sear it, but only if you prize a delectable, perfumed crust. Herb pastes are adaptable to your tastes. However, hardy herbs, such as rosemary and thyme, are better suited for extended cooking times than tender herbs.

A digital instant-read thermometer is a must for determining doneness -- but an oven-safe digital thermometer is better because it lets you monitor the lamb's temperature without opening the oven door.

Food Safety Precautions

The U.S. Department of Agriculture recommends cooking lamb to at least 145 F to reduce the risk of food-borne illness, particularly for high-risk groups such as pregnant women and children.