Oven Roasted Leg of Lamb

Why You’ll Love This Recipe

I love this recipe because it’s as elegant as it is foolproof. The prep is simple, but the flavors are rich and comforting thanks to the herb-garlic rub and a high-heat sear. Roasting the lamb alongside vegetables means everything finishes at the same time, and I only have one pan to clean. Plus, the leftovers are just as good the next day. It’s a beautiful, hearty main dish that always feels like a celebration.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the Lamb:

• 1 (5–6 lb) leg of lamb (bone-in or boneless)

• 2 cloves garlic, minced

• 2 tablespoons olive oil (plus extra for roasting)

• 1 tablespoon Dijon mustard

• 1 tablespoon chopped rosemary

• ½ tablespoon chopped thyme

• 1 teaspoon dried oregano

• 1 teaspoon salt

• Ground black pepper, to taste

For the Vegetables:

• 1.5 lbs baby potatoes, hasselbacked

• 4 large carrots, peeled and cut into chunks

• 1 tablespoon olive oil

• 1 tablespoon chopped rosemary

• Salt & pepper, to taste

• 2 heads of garlic, halved crosswise

Directions

1. I start by preheating the oven to 450°F and placing the empty roasting pan inside to heat—it helps get a beautiful sear on the lamb.

2. While the oven heats, I pat the lamb dry with paper towels. In a small bowl, I mix together the garlic, olive oil, Dijon mustard, rosemary, thyme, oregano, salt, and pepper. I rub this all over the lamb, making sure it’s coated evenly.

3. I carefully remove the hot roasting pan, add 1–2 tablespoons of olive oil, and place the lamb in the pan. I roast it for 10 minutes at this high heat to develop a crust.

4. After that, I reduce the oven temperature to 360°F and continue roasting. I cook the lamb to my preferred doneness—medium at around 145°F or well-done at 160°F. Depending on the size, this takes about 50–90 minutes.

5. About 30 minutes before the lamb is done, I remove the pan and scatter the hasselbacked potatoes, carrots, and halved garlic heads around the meat. I drizzle them with olive oil, season with salt, pepper, and rosemary, then return everything to the oven.

6. Once the lamb reaches the target temperature, I take it out and let it rest on the counter for 10 minutes before slicing. That rest time keeps it juicy and tender.

Servings and timing

This recipe serves 6 people generously. It takes 15 minutes to prep, 1 hour 30 minutes to cook, and about 2 hours total from start to finish. Each serving is about 475 calories and packed with protein and flavor.

Variations

Sometimes I swap out the carrots for parsnips, sweet potatoes, or Brussels sprouts. When I want an extra punch of flavor, I add a splash of lemon juice or red wine to the pan. If I’m cooking for a smaller crowd, I use a boneless leg of lamb and reduce the cook time accordingly.

Storage/Reheating

Leftovers keep beautifully. I store sliced lamb and roasted vegetables in airtight containers in the fridge for up to 3 days. To reheat, I warm the lamb in a 300°F oven wrapped in foil to retain moisture. I reheat the veggies in a skillet for best texture. Everything should reach an internal temperature of 165°F before serving again.

FAQs

Should I use bone-in or boneless leg of lamb?

Either works well. I like bone-in for presentation and flavor, but boneless is easier to slice and slightly faster to cook.

How do I know when the lamb is done?

I use a meat thermometer for accuracy. For medium, I cook it to 145°F. For well-done, I go to 160°F. It’s important to let it rest before slicing so the juices redistribute.

Can I prep this ahead of time?

Yes, I often season the lamb up to 24 hours in advance and keep it in the fridge. I bring it to room temperature for about 30 minutes before roasting.

What if I don’t have fresh herbs?

Dried herbs work too. I use half the amount if substituting dried rosemary or thyme since they’re more concentrated.

Can I make gravy from the pan drippings?

Absolutely. After roasting, I pour off the fat, deglaze the pan with a little broth or wine, and simmer it to make a flavorful sauce.

Conclusion

This oven roasted leg of lamb is one of my favorite showstopping meals that’s still easy enough for a laid-back dinner. It’s tender, juicy, and full of bold herb and garlic flavor. Roasted alongside golden potatoes and sweet carrots, it’s a complete one-pan meal that never fails to impress. Whether I’m serving it for a holiday or a quiet Sunday, it always feels like something special.

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