Roasted Boneless Leg Of Lamb
Published Feb 14, 2024
Updated Mar 11, 2025
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Create a showstopping main course for your next gathering when you make this Roasted Boneless Leg of Lamb.
Aromatic herbs, fresh minced garlic, and zesty lemon juice create an exceptionally succulent roast perfect for Christmas or Easter dinner and other special occasions.
This rich, tender leg of lamb will be the centerpiece at any dinner party or special occasions like Easter, Christmas, or Valentine’s Day. Pair it with Rosemary Garlic Mashed Potatoes or Sauteed Vegetables for a balanced, hearty meal.
For another mouth-watering lamb recipe, check out our Pan Seared Lamb Chops.
Table of Contents
Boneless Leg of Lamb Recipe
Working with larger cuts of meat than you’re used to can be intimidating, but don’t worry. I have easy-to-follow steps that make it simple for everyone, including beginner cooks!
Since this boneless leg of lamb recipe has you sear the meat in a cast iron skillet first, it creates a deeper color and gorgeous outer crust, locking in the juices.
Why You’ll Love This Recipe
- It requires little hands-on time. This easy lamb roast recipe doesn’t require much effort! The longest part of the process is marinating the meat. The rest of the preparation process is incredibly easy!
- The lamb has an excellent presentation. If you’re looking to impress your loved ones, this is certainly the recipe to make. Although it only requires a simple list of ingredients, it produces an elegant large roast perfect for holidays or small gatherings.
- It is extremely versatile. This juicy roast pairs with many different side dishes, giving you room for creativity. You can serve it with anything ranging from buttered leeks to glazed carrots to a mixed green salad! Plus, leftover lamb could make tacos, sandwiches, and more.
Ingredients Needed
To make this noteworthy entree, you only need a few simple ingredients:
- Boneless Leg of Lamb: Since it is boneless, you can cook it faster than a traditional whole roast leg. Then, when you butterfly it, it creates a larger surface area. This allows for more opportunities for sophisticated flavor since the marinade can penetrate more. You can get a boneless leg of lamb from grocery stores, or you can remove the bone from a leg of lamb.
- Fresh Rosemary and Thyme: Delicate, fragrant herbs enhance the lamb’s richness and depth of flavor. Fresh thyme and rosemary work well with lamb!
- Lemon Juice: This acidic component tenderizes the meat for better marinade absorption and brings a sense of lightness to the dish. You could also add lemon zest for more lemony flavor.
- Fresh Garlic: Using fresh garlic cloves instead of dried garlic powder makes all the difference in a pronounced garlicky flavor. This ingredient provides the dish with a pleasant umami kick.
- Mustard: This tangy ingredient supplies a contrasting taste to the sweet herbs and bright lemon juice, achieving a balanced flavor. You can use honey or Dijon mustard.
You will also need staples like salt, black pepper, and olive oil. Check out the recipe card below for all of the info!
How To Roast Boneless Leg Of Lamb
You can nail this recipe even if it’s your first time to make roast lamb. Here are the easy steps and step-by-step photos for making Roasted Leg of Lamb:
- Mix all of the marinade ingredients in a small bowl until thoroughly combined.
- Butterfly a boneless leg of lamb and rub the marinade on it. Roll it tightly, securing it with kitchen twine.
To butterfly a leg of lamb, make a lengthwise cut along the side of the meat to open it up. This method allows for quicker cooking and more even seasoning.
- Transfer the seasoned lamb to a bowl and tightly cover it with plastic wrap.
- Refrigerate the meat.
- Before cooking, take the lamb out of the fridge to come to room temperature. In the meantime, preheat the oven.
- Heat an oven-safe skillet until smoking hot.
- Sear the lamb in a cast iron skillet with olive oil on each side to give it a deep color.
- Loosely cover the meat with aluminum foil and transfer the skillet to the hot oven. You could also roast your leg of lamb in a roasting pan.
- Bake it to your desired doneness. The cooking time will depend on how you want the meat to be cooked. See the lamb cooking guide below. Use an instant-read thermometer to check the doneness of the meat.
Let the lamb rest for 10 to 15 minutes before slicing. This allows time for the meat to reabsorb its juices.
Substitutions and Variations
- Bone-In Leg of Lamb: You can surely use bone-in leg of lamb instead. Just keep in mind that it will take longer to cook. This isn’t an issue, though, as you will know when it’s done based on its temperature!
- Make it Spicy: Looking for a fiery kick? You can easily include cayenne pepper, crushed red pepper flakes, or smoked chili powder in the marinade blend.
- Make it a One-Pan Meal: After searing the meat, add quick-cooking vegetables to the pan, which will roast in the oven with the meat, creating an aromatic and flavorful dinner.
Leg of Lamb Cooking Guide
Everyone has their preferences when it comes to doneness. These temperatures can help you reach your preference much easier. Remember to place the instant read meat thermometer into the thickest part of the meat. You can check a few different spots to be safe!
- Rare: 125°F (51.6 °C) With a rare leg of lamb, the center is red and turns pinkish towards the outer part of the meat.
- Medium-Rare: 130°F (54.4 °C) to 135°F (57.2 °C) At this point, the center is pink, and the color slightly shifts towards a brown hue as it reaches the exterior portion.
- Medium: 135°F (57.2 °C) to 140°F (60 °C) Medium looks similar to medium-rare, except the center is a lighter pink color. With this doneness, the exterior is brown.
- Medium-Well: 150° (65.5 °C) to 155° F (68.3 °C) You won’t see any pink at this stage!
- Well-Done: 155°F (68.3 °C) to 165°F (73.8 °C) With well-done lamb, it is uniformly brown both inside and out.
It’s important to remember that the lamb leg will continue to cook for a short while even after you have removed it from the oven.
Therefore, I suggest taking it out of the oven when it’s at a temperature that is slightly lower than your desired temperature. This will help you achieve the perfect level of doneness.
Expert Tips For Roasted Boneless Leg of Lamb
- For best results, use a meat thermometer to check the internal temperature of the lamb. Otherwise, you might accidentally under or overcook the meat if you base its doneness only on its appearance.
- Use the right pan. If you don’t have a cast iron skillet or a braiser, you will have to transfer the seared leg of lamb to different cookware before putting it in the oven, which creates unnecessary dirty dishes.
- Allow the leg of lamb to rest for about 10-15 minutes before serving it. This results in maximum tenderness and juiciness!
Recipe Frequently Asked Questions
The boneless leg of lamb is not always butterflied. However, this recipe takes it a step further by butterflying it, which allows you to marinate the inside and then roll it up! If you don’t feel comfortable butterflying it yourself, you can ask the butcher to do it for you.
Although it isn’t mandatory, searing has several benefits, so I definitely recommend it. The process of searing gives the meat a deeper flavor and color, upgrading its taste and presentation. It also helps to create a seal so the juices remain inside!
Leg of lamb and lamb chops are similar in some ways, but they come from different parts of the lamb, which results in slight differences.
The leg of lamb is usually milder in taste, which makes it a good choice for people who don’t prefer a strong “gamey” flavor. Since it comes from the rear legs, it is leaner because the animal uses the leg muscles often.
It can become incredibly tender and juicy when roasted, and its flavor can deepen. On the other hand, lamb chops typically have a layer of fat, which contributes to a stronger “gamey” taste.
Serving
Enjoy this lamb roast with the following side dishes:
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Roasted Boneless Leg of Lamb
Ingredients
- 4-5 pound boneless leg of lamb
- 2 Tablespoons lemon juice freshly squeezed
- 2 Tablespoons olive oil
- 1 Tablespoon honey mustard or Dijon mustard
- 6 garlic cloves, minced
- 1¼ teaspoons salt
- 1 teaspoon ground black pepper
- 1 Tablespoon fresh minced rosemary
- 1 Tablespoon fresh minced thyme
- 2 teaspoons beef bouillon powder
- 1 Tablespoon olive oil for searing
Instructions
- Make the Marinade: In a small mixing bowl, combine the lemon juice, olive oil, honey mustard or Dijon mustard, salt, black pepper, minced garlic, rosemary and thyme, and beef bouillon powder.
- Prep and Season Lamb: Using kitchen scissors, cut out the netting from the lamb. Butterfly the lamb so it lies flat, with its interior facing you. Brush two-thirds of the marinade on the lamb's interior. Starting from the shorter side and working horizontally, roll the lamb tightly into a log. Tie tightly with kitchen twine, giving a 1-2 inch gap between each tie. Brush more of the marinade on the exterior of the lamb, reserving 1 tablespoon of the marinade for basting later.
- Let It Marinate: Place the seasoned lamb into a large mixing bowl. Tightly wrap the bowl with a plastic wrap and place in the fridge to marinate overnight or for at least 2 hours.
- Bring To Room Temperature: Remove the lamb from the fridge one hour before cooking. Preheat oven to 350℉ (180 ℃).
- Sear The Lamb: Set a 12-inch oven-safe skillet, preferably a cast iron skillet, on medium-high heat until smoking hot. Add the lamb to the skillet and let it cook for 4 minutes until it gets some color, then flip it over and let it cook for another 4 minutes. Using a tong to lift and support the lam, sear both sides for 3-4 minutes.
- Roast: Cover the lamb loosely with foil, transfer it to the preheated oven and let it roast for 30 minutes. After the first 20 minutes, remove the foil and let it continue roasting uncovered for another 10 minutes or until desired doneness. See the lamb cooking guide in the recipe notes.
- Rest: Once the lamb is roasted, transfer it to a cutting board, cover it with foil and let it sit for 10-15 minutes. Remove the twine, cut the lamb into slices, and serve it warm.
Notes
- Rare: 125°F (51.6 °C) With a rare leg of lamb, the center is red and turns pinkish towards the outer part of the meat.
- Medium-Rare: 130°F (54.4 °C) to 135°F (57.2 °C) At this point, the center is pink, and the color slightly shifts towards a brown hue as it reaches the exterior portion.
- Medium: 135°F (57.2 °C) to 140°F (60 °C) Medium looks similar to medium-rare, except the center is a lighter pink color. With this doneness, the exterior is brown.
- Medium-Well: 150° (65.5 °C) to 155° F (68.3 °C) You won’t see any pink at this stage!
- Well-Done: 155°F (68.3 °C) to 165°F (73.8 °C) With well-done lamb, it is uniformly brown both inside and out.
