Roast Leg of Lamb

updated Dec 21, 2023
christmas

Everything you need to know to roast a perfectly cooked leg of lamb for your holiday meal.

Serves10

Prep15 minutes

Cook1 hour 30 minutes

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You can have the turkey. Leave the glazed ham. Prime rib — what’s that? In my house, leg of lamb is the celebratory roast; I love its tenderness and flavor. Though roast leg of lamb sounds intimidating, the sweet little secret is that leg of lamb is actually one of the easiest, most foolproof cuts of meat to cook.

Here’s our remarkably simple, fuss-free leg of lamb recipe. It will turn out perfectly every time.

Quick Overview

Tips for Roasting a Leg of Lamb

  • Be sure to buy a bone-in leg of lamb (at a reputable butcher) for added flavor. While you’re at it, ask for your meat to be “market weight” and ask the butcher if they will trim it for you.
  • There’s no need to marinate a leg of lamb because the cut of meat is tender enough.
  • It’s recommended to roast a leg of lamb at 325°F and to cook it to medium-rare to medium (this would be about 20-25 minutes per pound on average).
  • To properly roast, rub the lamb with seasonings, broil it on both sides, top with rosemary and garlic, and then roast (covered loosely with foil) for about an hour.
Credit: Joe Lingeman

What Is a Leg of Lamb?

When we talk about lamb leg, we mean one of the back haunches of the animal, and the most common cut includes the upper part of the leg only. Think of the thigh, without the lower part of the leg.

Expert Tips for Buying & Cooking a Leg of Lamb

While I’ve cooked lamb on many occasions, cooking a whole leg can still feel intimidating (as opposed to a more beginner-friendly lamb chop recipe). It’s a large, expensive cut of meat, and I always wonder whether I am going to dry it out or make it tough. Should I marinate it? Should I do something special to make sure it’s cooked properly?

I spoke to my favorite local butcher, Bluescreek Farm Meats, in Columbus, Ohio, to learn a little more about leg of lamb and how to cook it.

Here are some expert tips from Jamie Smith at Bluescreek on what to look for in lamb, and how to cook it. A sneak peek: Cooking a leg of lamb is actually really, really simple.

Credit: Joe Lingeman

Does Leg of Lamb Have the Shank On or Off?

Usually leg of lamb is sold without the shank attached; you are just buying the upper part of the leg, as seen here, without the lower part. You can order a leg of lamb with the shank left on, however; this is sometimes called an “American leg,” but usually it’s simply referred to as “shank-on leg.”

Some people prefer this, as it looks more traditional and dramatic on a serving platter, but there’s no major advantage to having the shank (other than getting an extra soup bone!).

Credit: Joe Lingeman

Should I Get Boneless or Bone-in Leg of Lamb?

Smith prefers bone-in, for the flavor. Think of how we make stock from bones, she said. The bones hold so much of the flavor. When you roast a piece of meat with the bone still in, you are getting all that flavor in the meat itself. A bone-in lamb leg can be a little trickier to carve, but we opted for bone-in in this cooking lesson (don’t worry; we’ll show you how to carve it).

If you are really nervous about carving meat, boneless is fine; it’s easier to slice. If you buy a boneless leg of lamb, it will probably come in a net. When the bone is removed from the lamb, the meat needs to be held together in the shape of the leg for cooking, so heatproof, oven-safe netting is usually used. If your netting isn’t oven-safe, you can tie it up with kitchen twine instead (or ask your butcher to do it for you!).

What Should I Ask the Butcher When Buying Leg of Lamb?

  • Go to a quality and reputable butcher. A leg of lamb is expensive regardless of where you buy it, so we feel that the investment is best spent with a butcher who either raises the animals himself (as Bluescreek does on their farm) or who can tell you how the lambs were raised.
  • Ask for market weight. This means no baby lambs, and no lambs that are too old and verging on (tougher) mutton.
  • Ask if they can trim the lamb leg for you. This means that they will trim away the fell, a thick outer layer of fat (which is what can make lamb taste so strongly “mutton-y”), as well as any additional fat that you request to have removed. Personally, I like a nice pad of fat, which insulates the meat and keeps it tender.

Should I Marinate a Leg of Lamb?

“Lamb leg is a really tender cut,” said Jamie at Bluescreek. “You don’t need to marinate it.” In fact, she said, marinating lamb can actually make it tougher.

A marinade is designed to break down the tough fibers in meat, but since lamb is naturally so tender, marinating can destroy the integrity of the meat — the texture and flavor — and make it tough to chew. “I would not marinate a lamb leg for more than two or three hours,” said Jamie. “It’s fine to follow a recipe, but be cautious.”

To add flavor to the roast, we decided to skip marinating altogether and season it simply with herbs and garlic.

Ingredients You’ll Need to Roast a Leg of Lamb

  • Bone-in leg of lamb: Though bone-in can be trickier to carve, it adds more flavor to the dish.
  • Garlic: Adds a buttery seasoning on top of the lamb just before it goes in the oven.
  • Rosemary sprigs: Adds a rich, aromatic flavor to the leg of lamb.
  • Olive oil, salt, and pepper: This serves as the rub over the leg of lamb.
Credit: Joe Lingeman

Should I Cook a Leg of Lamb to Be Rare, Medium, or Well?

Personal preference should determine how long you cook your leg of lamb. Personally, I find rare and bloody lamb to be unappetizing. I prefer medium-rare to medium — still tender, with a hint of pink.

We calibrated our cooking lesson to this stage of doneness, but consult the cooking chart below if you like your lamb done differently. I will say that such a large cut of meat will probably have some variability; parts of the lamb leg were a little closer to medium, and others were closer to rare.

What Is the Best Temperature to Cook a Leg of Lamb?

Roasting Temperature: 325°F

  • Rare: 125°F (about 15 minutes per pound)
  • Medium-Rare: 130°F to 135°F (about 20 minutes per pound)
  • Medium: 135°F to 140°F (about 25 minutes per pound)
  • Well-Done: 155°F to 165°F (about 30 minutes per pound)

All of these cooking times take into account the fact that we broil the lamb first to sear it. They also assume a resting period of at least 15 minutes, during which the lamb actually continues cooking internally.

It’s best, especially if you like rare or medium-rare lamb, to take it out at a lower temperature than those officially recommended by the USDA.

REMEMBER! These times are only guidelines. Depending on many factors, your lamb leg may roast slower or faster. Check after one hour and then continue roasting, checking frequently, until the lamb reaches your desired internal temperature.

Tester’s Notes

A bone-in leg of lamb always surprises me with how easy it is to roast. This cut of lamb is so flavorful that all it needs is some garlic and rosemary. It may seem like a large piece of meat, but it’s great as a holiday table centerpiece or a hearty dinner on a weekend that leaves you with leftovers for sandwiches or salads for the week.

Carving a leg of lamb is actually easier than carving a whole chicken, and we’ve added some more photos to walk you through the whole process so that you have a beautiful serving platter of perfect lamb slices when you’re all done.

Christine, November 2018

How To Roast a Leg of Lamb

Everything you need to know to roast a perfectly cooked leg of lamb for your holiday meal.

Prep time 15 minutes

Cook time 1 hour 30 minutes

Serves 10

Nutritional Info

Ingredients

  • 1

    (5 to 7 pound) bone-in leg of lamb

  • 3 tablespoons

    olive oil

  • Kosher salt

  • Freshly ground black pepper

  • 6 cloves

    garlic, minced

  • Leaves from 3 fresh rosemary sprigs, coarsely chopped (about 1 tablespoon)

Instructions

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  1. Take the leg of lamb out of the refrigerator about an hour before cooking so it comes closer to room temperature. This promotes faster, more even cooking. Set the lamb in a rack inside a roasting pan. Drizzle with 3 tablespoons olive oil and rub all over into the fat and meat. Season generously all over with salt and pepper. Position the lamb so that it is fat-side down.

  2. Arrange an oven rack so that the top of the lamb is a few inches from the broiler element. Heat the broiler. Broil until the surface of the lamb looks seared and browned, about 5 minutes.

  3. Flip the leg over and put back under the broiler until the other side is seared, about 5 minutes more.

  4. Take the lamb out of the oven. Turn off the broiler and set the oven temperature to 325°F. Reposition the oven rack to the middle of the oven. Rub the top of the lamb with 6 cloves of minced garlic and 1 tablespoon coarsely chopped fresh rosemary.

  5. Tent the pan loosely with aluminum foil to keep the garlic and rosemary from burning. Put the lamb back in the oven and roast for 1 hour.

  6. Uncover the lamb. Take its temperature with an instant-read thermometer in the thickest part not touching bone. The lamb is ready when the temperature is 135°F or above. At 135°F the lamb is cooked to rare, but it will continue cooking as it rests, so we recommend taking it out of the oven at 135°F for medium-rare to medium. (Refer to the cooking chart above for general roasting times.)

    If the lamb is not ready, continue cooking uncovered until it reaches your desired internal temperature, checking the temperature every 20 minutes.

  7. Let the lamb rest for at least 15 minutes before carving. Transfer the lamb to a clean cutting board. The bone runs through the meat at an angle, giving you two fairly big pieces of meat on either side of the bone. Start with the side of meat that feels most accessible to you.

  8. Make straight, parallel cuts straight down through the thickest part of the meat until you hit the bone. You should be cutting perpendicular to the bone, across the grain of the meat. The slices will still be attached where they meet the bone.

  9. Turn your knife so that it's now parallel to the bone instead of perpendicular. Starting at the end of the bone furthest from you, cut through the slices where they attach to the bone. Keep your knife close to the bone so you get as much meat as possible, but don't worry about getting every single scrap of meat right now — just focus on cutting cleanly through the big slices and you’ll get any leftover pieces later.

  10. Place the slices on a serving platter. Tent the platter with foil to keep the meat warm.

Recipe Notes

To serve: We highly recommend serving the lamb with mint pesto.

Storage: Leftover lamb can be refrigerated in an airtight container for up to 3 days.

Freezing: Jamie recommends freezing leftover rare to medium-rare lamb in slices wrapped in foil. Then, to warm them, she puts the frozen slices, still wrapped, in a 350°F oven. This will warm them and not overcook them.