This easy roasted boneless leg of lamb recipe is quick to prepare. The lamb leg is flavored with a marinade of olive oil, garlic, lemon juice and fresh rosemary leaves, before being roasted in the oven.
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Lamb is a great-tasting meat, with a robust, almost gamy flavor. For this reason, it and can take on strong flavors like the garlic, lemon, and rosemary I’ve used in the marinade. I like to marinate the meat before roasting as it really intensifies the flavor of the meat and also stops the joint from drying out while roasting.
I have marinated this leg of lamb for as little as 30 minutes, but a 24-hour marination works well with this cut. The longer the marinade, the more intense the flavor.
Roasted leg of lamb is a great meat to serve, as a 5 pound boneless leg of lamb will easily serve eight people. This makes it a great alternative to more traditional roasts like turkey, chicken or beef during Thanksgiving, Christmas, or other holiday gatherings.
If you love to cook with lamb, be sure to try my Air Fryer Lamb Chops or my Moroccan Soup!
Ingredients
Here is what you will need for this recipe:
- Marinade– Olive oil, Garlic, Fresh rosemary leaves, Fresh Lemon juice, Kosher salt, and black pepper.
- Boneless leg of lamb (netted or wrapped in twine – get your butcher to do this)
How to roast boneless leg of lamb
Add olive oil, garlic cloves, rosemary leaves, lemon juice, kosher salt, and black pepper to a mini food processor and process until smooth.
Pat the lamb dry and rub the mixture over the lamb, getting the mixture into the netting. Cover and let the lamb marinate in the refrigerator for up to 24 hours.
When ready to roast, preheat the oven to 450 degrees Fahrenheit. Optional step: In a large cast iron skillet, add onion, garlic cloves, rosemary, and oil. Place the cast iron skillet in the oven for 10 minutes to get it nice and hot. When ready to roast the lamb, place the lamb on top of the hot skillet. This will give you delicious melted onions and garlic when done. You could also skip this step and roast your lamb in a roasting pan.
Place the lamb in the cast iron skillet on top of the onions, fat cap facing up. Roast the lamb at 450 degrees Fahrenheit for 15 minutes.
ProTip – use a leave-in probe themomter when roasting this lamb. It’ll monitor the temperature of your meat while it cooks, helping to ensure you remove the roast at the right temperature.
After 15 minutes, reduce the oven temperature to 325 degrees and continue roasting until the internal temperature of the lamb reaches your desired temperature (about 1 hour and 20 minutes for medium).
Remove the lamb from the oven and allow it to sit for 10-15 minutes. Then remove the netting, slice, and serve.
Boneless leg of lamb cooking time
When cooking lamb, the internal temperature varies depending on how you like your lamb cooked. The internal temperatures are as follows:
- Rare: 115-120F
- Medium rare: 125F
- Medium: 130F
- Medium-well: 145F
- Well-done: 150F
Expert Tips
These tips will help you make the best-roasted lamb leg you’ve ever tasted.
- If time allows, you can marinate the lamb for more flavor. Marinate in the fridge for up to 24 hours as a longer marinade time will improve the flavor.
- A probe thermometer is the easiest method of checking the internal cooking temperature of lamb, or any other meat, to ensure it is done.
- Once the lamb leg has finished cooking, remove it from the oven and set it aside to rest for 10-15 minutes before slicing and serving. This will allow the juices to be absorbed back into the lamb and results in moist and tender slices of meat.
Variations for this Boneless Leg of Lamb recipe
I make a simple marinade for the lamb using garlic, lemon, and fresh rosemary along with some salt and pepper. However, lamb is a great meat to add flavor to so here are some other suggestions if you want to mix things up.
- Ground spices: anise, cardamon, cinnamon, cumin, nutmeg
- Herbs: dill, garlic, mint, parsley, rosemary, thyme.
- Citrus: as well as the lemon juice, add some finely shredded lemon zest.
How to serve my roasted leg of lamb
When I’m served a roasted joint of meat, like this boneless leg of lamb, I like to serve a potato side and at least 2 other vegetable sides.
When it comes to great-tasting potato sides, you can’t beat my Creamy Instant Pot Mashed Potatoes, Garlic Mashed Potatoes, or my Cheesy Scalloped Potatoes. For a great alternative to regular potatoes, try my Mashed Sweet Potatoes or my Southern Candied Sweet Potatoes.
For vegetable sides try my Sweet & Spicy Air Fryer Brussels Sprouts, Instant Pot Buttered Cabbage, Southern Green Beans, Air Fryer Carrots or Marinated Air Fryer Vegetables.
How to store roasted leg of lamb
To refrigerate: Keep any leftover lamb in an airtight container in the fridge for 3-4 days.
To freeze: Once cooked and cooled, slice the leg of lamb and place it into an airtight container and store in the freezer for up to 3 months. Defrost overnight in the refrigerator when you are ready to enjoy.
FAQs:
Either cut can be roasted, however I prefer to use a boneless leg of lamb is it cooks faster than a bone-in joint as a bone acts as an insulator, meaning you have to cook a bone-in leg longer.
I start with a high roasting temperature of 450 degrees Fahrenheit for the first 15 minutes of the cook. Then I reduce the oven temperature to 325 degrees Fahrenheit for the remainder of the cook.
The marinade of olive oil and lemon juice not only flavors the lamb, but helps to keep it moist during the cooking process.
You don’t need to marinate the lamb leg before you roast it, however it will add great flavor to the finished meat and also stops the joint from drying out. A short marinade of 30 minutes will do if you are pushed for time, but allow longer for a more intense flavor.
No, you don’t need to cover a leg of lamb while it is roasting as this is a fairly quick roast and you want the skin to crisp up nicely.
I recommend slicing the meat across the grain as this cuts across the muscle fibers. This ensures the most tender slices of roast lamb and avoids the meat being chewy.
If you have tried this Roasted Boneless Leg of Lamb recipe, or any other recipe on my blog, then please rate it and let me know how it turned out in the comments below!
Roasted Boneless Leg of Lamb
Ingredients
- 1/4 cup olive oil
- 6 cloves garlic
- 3 Tablespoons fresh rosemary leaves
- 2 Tablespoons lemon juice
- 2 teaspoons kosher salt
- 1/2 teaspoon black pepper
- 5 lb boneless leg of lamb netted or wrapped in twine
- yellow onion, garlic cloves, additional rosemary optional
Instructions
- Add olive oil, garlic cloves, rosemary leaves, lemon juice, kosher salt, and black pepper to a mini food processor and process until smooth.
- Pat the lamb dry and rub the mixture over the lamb, getting the mixture into the netting. Cover and let the lamb marinate in the refrigerator for up to 24 hours.*
- Preheat the oven to 450 degrees Fahrenheit.
- Place the lamb in a roasting pan, fat cap facing up. Roast the lamb at 450 degrees Fahrenheit for 15 minutes.
- After 15 minutes, reduce the oven temperature to 325 degrees and continue roasting until the internal temperature of the lamb reaches your desired temperature (about 1 hour and 20 minutes for medium).
- Remove the lamb from the oven and allow it to sit for 10-15 minutes. Remove the netting, slice, and serve.
Notes
- Optional step: In a large cast iron skillet, add some onion, garlic cloves, rosemary, and about 2 Tablespoons of oil. Place the cast iron skillet in the oven for 10 minutes to get it nice and hot. When ready to roast the lamb, place the lamb on top of the hot skillet. This will give you delicious melted onions and garlic when done. You could also skip this step and roast your lamb in a roasting pan.
- You can skip the long marination and allow the lamb to marinate for as little as 30 minutes.
- I recommend using a probe thermometer to monitor the temperature of the lamb while it is in the oven.
- Lamb Cooking Temps are as follows:
- Rare: 115-120F
- Medium rare: 125F
- Medium: 130F
- Medium-well: 145F
- Well-done: 150F
Tim Tizon
Wednesday 14th of December 2022
So delicious and extra ordinary recipe
Tanya
Saturday 17th of December 2022
Thank you Tim :)