It’s mind-boggling, really. How can just four ingredients turn out such a lovely main course? And in only about two hours. I was doubtful; The One (Who Brings Me Love, Joy, and Happiness) was even more doubtful.
And if I’m 100% transparent, our first attempt was a…disaster. The meat was extremely tough, sinewy–basically inedible. We made a meal of lemon-flecked mashed potatoes, roasted broccoli rabe, and my favorite Hershey’s chocolate cake.
I was ready to nix the recipe, but it comes from the unimpeachable America’s Test Kitchen. These folks are as obsessive as we are about delivering recipes that work. Then, I read my recipe testers’ reviews. All raves—I mean RAVES.
Clearly, something was wrong.
At a loss, I headed to my favorite butcher for a chat. He peppered me with questions. Rather than going the extra step and buying the leg of lamb from him and having him fully trim and tie the roast, I picked up one of those legs in a red-net bag at Costco. (I know, I know…)
“It has to be the quality of the lamb and the quality of the butchering,” he said, “because the leg is one the most tender cuts of lamb.”
Feeling a bit chided, I bought a leg of lamb from him and had him carefully remove the silver skin (the tough connective tissue) from the inside, trim excess fat, and tie it up. What a difference!
Moral of the story? Do yourself a favor and have the leg properly prepped—either by you or your butcher—and you’ll have a wonder of a wonderful meal.
Chow,
Why This Recipe Works
This roasted leg of lamb recipe works because it combines simplicity with flavor. By using a low and slow cooking method, the lamb becomes incredibly tender and juicy. The high heat searing at the start creates a flavorful crust, while the low-temperature cooking ensures a perfectly cooked interior. The addition of garlic and rosemary infuses the meat with aromatic flavors.
Ingredients at a Glance
- Leg of lamb—For this recipe, you’ll need a boneless half-leg of lamb, which is available at some supermarkets. You can also ask your butchers to cut one for you. Make sure to they properly trim the silver skin and excess fat and tie it for you. It makes all the difference.
- Fresh rosemary–When purchasing rosemary, choose fragrant stalks with bright green leaves and avoid any rosemary that has brown leaves.
How to Roast a Boneless Leg of Lamb
- Crank the oven to 250°F (120°C). Pat the lamb dry and season it all over with salt and pepper. Heat the oil in a large Dutch oven.
- Brown the lamb on all sides in the hot oil. Transfer to a plate. Pour off any fat in the pot.
- Return the lamb and any accumulated juices to the Dutch oven, then tuck in the garlic and rosemary.
- Cover the Dutch oven with foil, then top with the lid. Roast the lamb until it reaches the desired doneness.
- Transfer the lamb to a platter and tent loosely with foil. Let rest for 20 minutes before carving.
Common Questions
For a boneless leg of lamb, I recommend cooking it medium-rare (130°F to 135°F/54°C to 57°C), which will give you tender, juicy meat. If you prefer your meat a little more done, roast it medium-well (140°F to 145°F/160°C to 63°C). Save the very well-done lamb (160°F/ 71°C and above) for tougher cuts, like slow-roasted lamb shoulder.
Don’t overcook it! Because leg of lamb is a lean cut and doesn’t have many tough muscles, it is best served medium-rare, when it will be at its most tender. Use an instant-read thermometer to check the internal temperature, and remember that the temperature will continue to rise 5 to 10 degrees while it rests.
What to Serve with this Lamb dish
Oh, so many options! Try serving your roast lamb with braised new potatoes and roasted carrots with allspice for a well-balanced meal.
Helpful Tips
- If your lamb has a lot of fat, be sure to trim it (or have your butcher do it), as this will help to reduce the gamey flavor of the meat.
- To scale the recipe for a larger or smaller leg of lamb, cook it for 15 to 20 minutes per pound for medium-rare.
- This recipe is suitable for gluten-free and dairy-free diets.
Storage and Reheating
Store leftover lamb in a sealed container in the fridge for up to 4 days or freeze it for up to 2 months. To reheat the lamb, place it in a covered baking dish with a little of the jus and heat in a 300°F (150°C) oven until warmed through.
More Luscious Leg of Lamb Recipes
Write a Review
If you make this recipe, or any dish on LC, consider leaving a review, a star rating, and your best photo in the comments below. I love hearing from you.–David
Slow Roasted Boneless Leg of Lamb
Ingredients
- One (4-pound) boneless half leg of lamb, trimmed of silver skin and excess fat and tied
- Salt and freshly ground black pepper
- 2 tablespoons extra-virgin olive oil
- 8 cloves garlic, peeled and thinly sliced
- 2 sprigs fresh rosemary
Instructions
- Set a rack on the lowest level of the oven and crank the heat to 250°F (120°C).
- Use paper towels to pat the lamb dry, then season it generously all over with salt and pepper.
- Pour the oil into a large Dutch oven. Set it over medium-high heat and let the oil heat until it just begins to smoke.
- Carefully lower the lamb in the pot and brown on all sides, about 15 minutes. If the pot begins to scorch, reduce the heat. Transfer the seared lamb to a large plate.
- Pour off any melted fat from the pot. Return the lamb and any juices to the Dutch oven, and tuck in the rosemary and garlic.
- Cover with a large piece of foil, then the lid. Cook until the lamb reaches your desired doneness, about 1 hour for medium-rare (125°F | 52°C), depending on the size of your roast.
☞ TESTER TIP: Remember, the internal temperature will continue to rise to about 135°F, which is medium-rare, as the roast rests.
- Transfer the lamb to a cutting board and tent loosely with foil. Let it rest for 20 minutes.
- Slice the lamb into 1/4-inch-thick (6-mm) slices and arrange on a serving platter. Strain the jus in the pot and drizzle it over the lamb.
Notes
- Trim the fat and connective tissue—If your lamb has a lot of fat, be sure to trim it (or have your butcher do it), as this will help reduce the meat’s gamey flavor. Removing the connective tissues ensures a tender bite.
- Scaling–To scale the recipe for a larger or smaller leg of lamb, cook it for 15 to 20 minutes per pound for medium-rare.
- Storage–Store leftover lamb in a sealed container in the fridge for up to 4 days or freeze for up to 2 months.
- Dietary–This recipe is suitable for gluten-free and dairy-free diets.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Recipe Testers’ Reviews
I brought this to Easter dinner, and everyone raved about how tender and flavorful the meat was. It’s easy, decadent, tender, and juicy—everything you’d want in a beautifully cooked roast. The fact that it creates its own perfectly seasoned jus is just the icing on the cake.
My boneless leg of lamb weighed 7.17 pounds. Since my meat was a few pounds heavier than the recipe specified, I cooked it for an hour and set the temperature to 98 degrees. This wasn’t surprising, so I popped it back in for 45 minutes until it was 122 degrees. I wasn’t pleased with the browning I’d done on the top, so I broil it for 10 minutes to get better coloring.
After resting for an hour, I carved the lamb roast and drizzled the jus with the garlic over the top. It was perfectly medium (I would have cooked it less, but this was for a bunch of people, not just my heathens and me). It’s our tradition to serve lamb with mint gravy, so that was served alongside.
This roasted boneless leg of lamb could be a Testers Choice Selection for the garlic-and-rosemary-infused lamb jus alone. I made the recipe exactly as written and wouldn’t change a thing.
The simple ingredients transformed into something new and exciting during their stint in the oven. The lamb was tender, full of flavor, and perfectly cooked. My roast was a bit smaller than called for (2.2 lb/1 kg) and was cooked to medium-rare after 40 minutes.
The jus was rich and perfectly balanced. And did I mention that garlic? I served this for an Easter/Passover dinner with matzo ball soup followed by the lamb with tiny boiled potatoes and steamed string beans. We had a Spanish Tempranillo that was aged in a whiskey barrel, which is quite heavy, and it paired very nicely with the lamb.
A 4-pound lamb roast will easily feed eight people. Keep in mind that this equates to almost 8 ounces of meat per person, which, with starch, vegetables, and bread (to soak up the juices, of course!), is more than enough to have leftovers for luscious lamb sandwiches for that late-night snack.
I spent about 20 minutes preparing everything, trimming and tying the roast, and warming the Dutch oven. A large portion of that time was spent tying the roast because I am TERRIBLE at it. I used an 8-qt Dutch oven, browned the lamb, starting with the fat side down, and then drained the fat. Again, I feel like discarding as much fat as possible contributes greatly to losing the gaming flavor often found with lamb roasts.
I was careful not to leave the garlic and rosemary in the hot Dutch oven very long before adding the roast and accumulated juices. Otherwise, the garlic can start to burn, and the rosemary gets a bitter flavor from the oils overheating.
I served this with one-pot sausage meatball pasta, the brown bread soft baguettes from Cheesecake Factory (don’t judge me; it makes phenomenal snack-size sandwiches later with a bit of horseradish mayo), a salad, and red wine.
You can never go wrong with the classic combination of rosemary and garlic for lamb. You also can’t go wrong with the method described here of slow-roasting lamb en cocotte.
This roasting technique was a surprise to me, and I can’t imagine roasting a boneless leg of lamb any other way! Perfectly moist and perfectly cooked lamb is what you’ll achieve with this method.
Another surprise was that the lamb cooked to medium rare in just one hour at 250 degrees. I actually put the lamb in the oven one hour early to prepare for the possibility that the lamb would need more time to cook. It didn’t!
But I have to say that letting the lamb rest in the pot (with the lid off) for the next hour or so until serving time was a good call, and I’ll let the meat rest for an hour when I do it again. The juices stayed in the meat and didn’t escape when I sliced into it.
The meat was perfectly rosy throughout and very juicy. Another bonus of cooking en cocotte is that there was a lot of lamb jus to be had. I simply poured the juices into a pitcher for serving. There was almost no fat, as I had trimmed much of the fat (as recommended) before roasting.
A final comment: Usually, when you roast a boneless leg of lamb, you’ll get some medium-rare sections along with some more well-done sections. I honestly did not find this to be the case with this cooking method. The meat was quite uniform throughout, with no dry or overcooked parts.
I served this with an orzo and asparagus pilaf and a platter of roasted carrots with pistachios. Choose your favorite red wine to go with this, and you’ll have a special meal for very little effort.
This is a quick and easy way to make a lamb dinner. I used a 2.2-pound leg of lamb because there were only two of us. Trader Joe’s boneless legs of lamb average between 1.5 to 2.2 pounds, so that is perfect for downsizing the recipe. We had plenty of leftovers, which should make lovely lamb sandwiches.
The instructions are clear and concise–no mystery or surprises here. I cooked the lamb for 45 minutes, and it was perfectly done. As I like it a little rarer, the next time I make it, I will check at 30 minutes if using the same-size leg of lamb.
I served this with a frisée salad with a mustard vinaigrette and black pepper mashed potatoes. It would be great with roast potatoes as well.
I wanted to “test drive” this before Christmas to make sure it worked. And BOY did it ever! I followed the recipe exactly. (I almost–almost–never mess with a David Leite recipe!) WE all loved it. The flavor was great–simple and elagant. I served it with the garlic mashed potatoes and sauteed green beans on this site. A perfect practice dinner. Now, on to the main attraction of Christmas!!
Tully, I’m so delighted you enjoyed the recipe. i hope your Christmas guests enjoy the leg of lamb as much as you. Merry, merry. Happy, happy!