Slow Roasted Boneless Leg of Lamb

Slow Roasted Boneless Leg of Lamb is a tender, flavorful centerpiece that’s perfect for special occasions or a cozy weekend dinner. The meat roasts low and slow until it’s fork-tender, infused with garlic, herbs, and rich, natural juices. It’s the kind of dish I love serving when I want something elegant but comforting—and the leftovers are just as good the next day.

Why You’ll Love This Recipe

I love how this boneless leg of lamb turns out juicy and full of flavor with minimal effort. The long, slow roast lets the meat stay moist and tender while building incredible flavor from the herbs and garlic. It’s easy to season ahead of time, toss in the oven, and let it cook while I prep sides or enjoy time with guests. This is one of those recipes that always impresses without being fussy.

Ingredients

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

• Boneless leg of lamb, rolled and tied (about 3–4 pounds)

• Olive oil

• Garlic cloves, minced or slivered

• Fresh rosemary, chopped

• Fresh thyme or oregano (or dried herbs)

• Lemon zest and juice

• Salt and black pepper

• Optional: red wine or beef broth (for pan juices)

• Optional: carrots, onions, or potatoes (for roasting with the lamb)

Directions

1. I preheat the oven to 275°F and bring the lamb to room temperature for about 30 minutes.

2. I make a paste with olive oil, garlic, rosemary, thyme, lemon zest, salt, and pepper.

3. I pat the lamb dry and rub the herb paste all over, pressing it into the meat.

4. I place the lamb in a roasting pan, fat side up. If using veggies, I scatter them around the lamb with a splash of olive oil and seasoning.

5. I roast uncovered for 3.5 to 4 hours, or until the internal temperature reaches 135°F for medium-rare or 145°F for medium.

6. I remove the lamb and let it rest, loosely covered, for 15–20 minutes to allow the juices to redistribute.

7. While it rests, I deglaze the pan with a splash of red wine or broth, scraping up the browned bits to make a simple jus.

8. I slice the lamb and serve it with the pan juices drizzled over the top.

Servings and timing

This recipe makes about 6–8 servings.
Prep time is 15–20 minutes, roasting takes 3.5 to 4 hours, and resting time is another 15–20 minutes. I usually plan for around 4.5 hours total.

Variations

• I sometimes stuff the center of the lamb with extra garlic, herbs, or spinach before tying it up.

• For a Mediterranean twist, I add kalamata olives and cherry tomatoes to the roasting pan.

• A rub of Dijon mustard with the herbs gives the meat a zesty crust.

• If I want a smoky edge, I finish the roast under the broiler for the last 5 minutes.

• Adding a drizzle of honey or balsamic to the herb mix adds a hint of sweetness.

storage/reheating

I store leftovers in an airtight container in the fridge for up to 4 days. To reheat, I cover slices with foil and warm them in a 300°F oven with a splash of broth or pan juices to keep them moist. The microwave works too, but I heat gently to avoid drying out the meat.

FAQs

Do I need to marinate the lamb overnight?

It’s not required, but I sometimes rub it with herbs and refrigerate overnight for deeper flavor. Just bring it to room temp before roasting.

What’s the best internal temperature for lamb?

I aim for 135°F for medium-rare and 145°F for medium. I always rest it before slicing so it stays juicy.

Can I cook this in a slow cooker?

Yes, but it will have a different texture. I sear the lamb first, then cook on low with broth and herbs for 6–8 hours until tender.

Can I make this recipe ahead of time?

Yes, I roast the lamb, let it cool, then slice and reheat gently in its juices before serving.

What should I serve with this lamb?

I love pairing it with roasted potatoes, garlic mashed cauliflower, lemony green beans, or a fresh herb salad.

Conclusion

Slow Roasted Boneless Leg of Lamb is one of my favorite ways to bring comforting elegance to the table. With its herbaceous crust and melt-in-your-mouth texture, it’s perfect for holidays, family dinners, or anytime I want to treat myself to something special. Once it’s in the oven, it practically takes care of itself—and every slice is worth the wait.