You can make a tender and juicy Roasted Boneless Leg of Lamb with just 15 minutes of prep and less than 2 hours of roasting time. A beautiful way to feed a hungry group of people, it's a roast that's perfect for your Easter table, but also wonderful for family meals and dinner parties all year long.
Most of us are used to cooking chicken, pork and beef, but cooking a leg of lamb can be daunting. But I promise that if you follow this simple recipe, you'll be rewarded with a mouthwatering meal with very little effort.
Jump to:
Ingredients You Need To Make Roasted Boneless Leg of Lamb
- Olive Oil: Good, extra-virgin olive oil.
- Dijon mustard: I recommend creamy.
- Garlic: Firm, plump cloves with smooth, silvery skin.
- Herbes de Provence: Or a blend of dried herbs and minced fresh rosemary.
- Kosher Salt: Quantity based on Diamond Crystal brand kosher salt - note that other brands such as Morton are almost twice as salty, so adjust the amount accordingly or to taste.
- Black Pepper: Ideally freshly ground.
Keys to Success
It all starts with prepping your lamb leg, unrolling it and trimming off excess fat and tendon. Then you'll massage it, inside and out, with a fragrant blend of olive oil, fresh garlic, Herbs de Provence and creamy Dijon mustard before rerolling and securing with kitchen twine. In the oven it will tranform into a succulent boneless lamb roast with a crisped, herbaceous crust.
If you're fortunate enough to have leftovers, make lamb sandwiches (extra mustard for me!) or breakfast hash (like this Corned Beef Hash).
FAQ
Lamb pairs well with many seasonings, but these are among the best: garlic, mint, mustard, onion, parsley, black pepper, rosemary, and thyme.
Herbes de Provence are a dried herb blend often used in French cuisine. The herb blend varies by brand, but often includes rosemary, thyme, marjoram, savory, oregano, and sometimes lavender (though it wasn't in the original French version). Some blends also include fennel seed, bay leaf, and/or tarragon.
Though both are delicious, boneless leg of lamb has some distinct benefits. It cooks faster and is easier to carve. It fits easily into roasting pans and, for the weight you get more meat (though you'll likely pay more per pound than a bone-in leg of lamb).
Yes, absolutely. In fact fresh rosemary has more flavor and the leaves are less woody than their dried counterparts. For this recipe, there is some rosemary in the dried herb blend, but you can embellish the herb rub with minced fresh rosemary leaves for more robust flavor.
The key to tender lamb is to not overcook it. Use an instant read thermometer to be sure that you pull it from the oven at the proper time, 10˚F before it reaches your desired temperature as the cooked meat's internal temperature will rise after you remove it from the oven). Target temperatures: Medium-Rare 145˚F, Medium 160˚F, Well-Done 170˚F.
What to Serve Alongside
- Gratin Dauphinois (Creamy classic French potato gratin.)
- Lyonnaise Potatoes (Another delicious French potato side dish with caramelized onions that's made on your stovetop.)
- Fondant Potatoes (These meltingly tender potatoes start on the stovetop and can finish in the oven while your lamb roast rests.)
- Mashed Red Potatoes (Ultra creamy with a method that might surprise you.)
- Brioche Dinner Rolls (Tender, buttery and so easy to make with this no-knead recipe.)
- Sugar Snap Pea Salad (The perfect pair to roast lamb if you're making it in the springtime.)
- Strawberry Spinach Salad (With pecans, goat cheese, and a tangy, honey sweetened balsamic vinaigrette.)
- Strawberry Spinach Walnut Salad (A riff on the salad above with walnuts and a Strawberry Vinaigrette.)
- Caesar Salad (Because you can never go wrong with this classic salad.)
How to Make Roasted Boneless Leg of Lamb
Step 1: Whisk together Dijon herb paste ingredients.
Step 2: Untie and unroll boneless leg of lamb. Trim away excess fat from both sides of the leg. Rub underside with ⅓ of herb paste. Re-roll roast and secure at ends and center with kitchen twine. Rub top with remaining herb paste and place on oven safe baking rack set inside foil lined rimmed baking sheet.
Step 4: Roast in a preheated 425˚F oven for 15 minutes. Reduced heat to 350˚F and roast 1 to 1 ½ hours more, until an instant read or meat thermometer inserted into the center reads 135˚F for medium rare. Remove roast and let stand 15-30 minutes before slicing. Slice and serve.
Recipe Video
Roasted Boneless Leg of Lamb
Ingredients
- 5 ½ pound boneless leg of lamb
For the Dijon Herb Paste
- ¼ cup extra virgin olive oil
- 2 tablespoons Dijon mustard
- 4 medium garlic cloves minced
- 2 tablespoons dried Herbes de Provence (recipe note #1)
- 1 tablespoon kosher salt (recipe note #2)
- ½ teaspoon freshly ground black pepper
Instructions
- Place an oven safe rack inside a rimmed baking sheet lined with foil (for easy cleanup).
- If lamb roast is tied, untie and unroll. Trim away thick areas of fat and tendon from the top and bottom of the roast, leaving a thin layer of fat on top.
- Whisk together all Dijon Herb Paste ingredients in a medium bowl until they emulsify into a uniform paste.
- Spread ⅓ of herb paste all over underside of roast. Roll roast back up into its original shape and snugly tie in the center and at both ends with three lengths of kitchen twine. Rub outside all over with remaining herb paste. Transfer roast, seam side down, to rack on prepared baking sheet and let stand at room temperature while the oven preheats.
- Preheat oven to 425°F.
- Roast lamb in hot oven for 15 minutes. Reduce heat to 350˚F and cook until an instant read thermometer inserted into the center registers 135˚F (for medium rare - the temperature will rise as the roast rests before slicing), 1 to 1 ½ hours. Transfer roast to cutting board; let stand 15-30 minutes before slicing.
- Snip twine with kitchen shears; remove and discard. Slice roast thinly (about ¼-inch) and arrange on platter. Serve.
Notes
- If you love the combination of rosemary and lamb, use 1 tablespoon of Herbes de Provence and 1 tablespoon of minced fresh rosemary. And / or to add brightness to herb paste, stir in 1 teaspoon of fresh lemon zest or more.
- Quantity based on Diamond Crystal brand kosher salt - note that other brands such as Morton are almost twice as salty, so adjust the amount accordingly or to taste.
Fantastic. I've done this a few times for the family now and it's a reliable favorite. Juicy and perfectly done each time. The paste and high starting temperature produce a lovely crust. The timings are about right but absolutely do use a meat thermometer, and start checking before time, to make sure you get it exactly to your liking. Mine were done a little sooner.
That's wonderful to hear, DavidH! Thank you for your cooking notes.
The paste was absolutely delicious, except a bit too salty because I used the Morton Kosher salt. After 15 minutes of cooking, the house smelled wonderful. I am keeping your recipe and will pass it on to anyone who asks. 🙂
I'm so glad you enjoyed it, Marguerite! Yes, it's amazing how much saltier Morton kosher salt is compared to Diamond Crystal brand.
This was THE best recipe I've ever had for lamb, so tender and flavorful! Thank you, it's a keeper!
My pleasure, Joanne! I'm so glad you enjoyed it. Thanks so much for coming back to let me know.
I made this last night and it's become an instant family favourite ... when my fussiest eater says "you can make that again, Mum", you know it's a winner! I teamed it with a side salad (it was a 40 degree day here in Australia) and a red wine reduction which teamed beautifully.
I love to hear this, Helen! I'm so happy to hear that this dish is a hit for you and your family!
Is one tablespoon of Kosher salt correct? It was way too salty for us and I ended up having to scrape the paste off the lamb after it was cooked and unfortunately it was still much to salty for our taste buds. Very easy to follow the recipe though, so thank you for that!
Hi Sofia! I use Diamond Crystal brand kosher salt and I'm wondering if you're using Morton brand (it's about twice as salty by volume). I should have noted the brand I use in the ingredient list and have added it now. As far as the quantity of salt, it's actually well below what some reputable sources recommend (for example, America's Test Kitchen recommends 1 teaspoon of kosher salt per pound of lamb roast), but it's all about how it tastes to you, so I'm so sorry that the seasoning was off for you and your family.
Thank you for your reply. I did use Morton!! I had no idea that it differed that much?! Will try and look for another brand, or simply cut back on the amount next time. It was a great recipe so will definitely use it again. Thank you!
My pleasure, Sofia!
Delicious!!
I'm so glad you enjoyed this, Dianna!
Just enjoyed a small lamb roast (1.64 lbs) adjusted cook time and made the suggested Lyonnaise potatoes. Delicious!! Your paste recipe is very similar to what i came up with when i do a rack of lamb. additionally, We roll rack in panko and chopped nuts (walnuts or macadamia).....but that wouldn't work for this. Your recipe is a keeper! Thank you
Thank you, Bianca - for your kind words and your cooking notes! So glad you're enjoying the recipe.
I made this roast tonight, doing everything Marissa recommended: trimming the fat and mixed all the ingredients to cover the meat with delicious flavour. It was so delicious! I've been making roast lamb for a number of years and this simple recipe was the best of all. Her suggestions about when to remove it from the oven meant the meat wasn't over done, but tender and cooked just to the spot between rare and medium. Thank you so much!
You made my day, Riesah! I'm so glad you're enjoying the recipe.
This was my first attempt at cooking boneless leg of lamb and it turned out great. I purchased my meat from Costco and it was 5.72lbs, followed your instruction and I am greatly pleased. My meat is juicy and cooked to medium on the end pieces and medium rare in the middle, just the way I like it.
That's wonderful to hear, Sharon! Thank you for coming back to let me know.
I have only a 2-lb. lamb roast on hand. Q: Will it work if I simply halve the recipe and reduce the cooking time by half here, or would some other adjustments be recommended? Thank you kindly for your reply.
Hi K.K.! Once you cook for the initial 15 minutes at the higher temperature, the roast will need another 15 to 20 minutes per pound. That said, be sure to check with a meat thermometer (ideally instant read) and take the roast out of the oven when it registers 135˚F in the thickest part for medium-rare and let rest until it reaches the target temperature of 145˚F. I hope that helps!
Is it OK to prepare and let marinate overnight then cook the next day?
Hi Al! Yes, absolutely.
Very easy and turned out great!
After seeing the comment below "Just hope I don't overcook it. Don't have thermometer", I just want to stress the importance of paying the price for a high quality oven thermometer (to measure oven temp - don't trust the setting level on oven), a leave-in probe thermometer and an instant read thermometer. I find cooking guidelines (x minutes per pound) to be highly inaccurate as meats often increase in temp slowly and then do a rapid rise towards the end. The time window for the perfect temp you want is very narrow.
That's wonderful to hear, Jeff! So true that every oven is a little bit different and good thermometers are indispensable kitchen tools.
OH MY GOODNESS!!! My husband and I had never had lamb. I made this and it was wonderful! Thank you for the very easy directions.
So brave to start off with a roast, Tess! I'm so happy that you and your husband enjoyed it so much. Thank you for coming back to let me know.
It was perfectly delicious!
So glad you enjoyed it, Luwayna!
After turning heat down to 350⁰, how many more minutes per pound should I leave in oven?
Hi Joyce! After the initial 15 minutes at the higher temperature, I find that the roast takes another 15 to 20 minutes per pound. That said, I recommend testing for doneness with a meat thermometer (pull the roast when it registers 135˚F in the thickest part for medium-rare and let rest until it reaches the target temperature of 145˚F).
Made this last Sunday for me and hubby; we’re big lamb lovers! I didn’t use any mustard but made ‘paste’ from herbs from my garden- parsley, rosemary, fresh garlic, and some Italian herb blend. I also didn’t retwine. It was amazing- perfectly med-med rare. Thank you for the recipe.
Hi Cathy! So glad that you and your husband enjoyed it and that you used herbs from your garden!
Just put in oven! Smells great can't wait.... Just hope I don't overcook it. Don't have thermometer
I hope it turns out beautifully, Jessie!
Believe it or not, but I've never actually cooked a leg of lamb. As you noted, there is a bit of a mystique around lamb. However, this recipe looks straightforward and delicious! Perfect for a fancier spring meal!
Oh wow, David! You've got to give this a try - I think you'll love it!
Marissa, that's one beautifully roasted leg of lamb! I am a huge fan of lamb (well, I love red meat 🙂 ) and I love rare. The Dijon herb paste is perfect.
Thanks, Angie. We're simpatico!
This looks just delicious Marissa! And so perfect for any major holiday, especially Easter! A total showstopper and so easy too!
Thanks so much, Mary Ann!