Slow Roasted Lamb Leg Recipe – Tender, Juicy, and Packed with Flavor
If you’re looking for a show-stopping dish that requires minimal effort but delivers maximum flavor, this Slow Roasted Lamb Leg Recipe is exactly what you need. Unlike traditional roast lamb, which is cooked quickly for a pink, medium-rare center, this recipe takes a different approach—slow roasting at a low temperature until the meat is fall-apart tender. The result? A beautifully juicy, deeply flavorful dish where the meat practically melts in your mouth.
Perfect for family gatherings, Sunday roasts, or holiday dinners, this roasted lamb leg recipe is incredibly forgiving, meaning you don’t have to stress about overcooking. The secret lies in partially submerging the lamb in a broth while roasting it covered for most of the cooking time. This technique ensures that the meat stays moist, absorbs all the aromatic flavors, and develops an incredibly rich taste.
In this post, I will walk you through how to cook a slow roasted leg of lamb, offering tips on seasoning, cooking times, and serving suggestions so you can achieve perfect results every time.
Not interested in lots of theories? Please feel free to jump directly to the recipe card.
Why This Slow Roasted Lamb Leg Recipe Works
✔ Fall-apart texture – The slow roasting process transforms the meat into fork-tender perfection, so there’s no need for carving—just use tongs to pull apart the juicy shreds.
✔ Rich, deep flavors – Cooking the lamb with garlic, onion, and rosemary infuses it with a bold and savory taste, while the broth keeps it moist and enhances its natural richness.
✔ Minimal effort – Once it’s in the oven, most of the work is done. No complicated techniques, no frequent basting—just let it cook low and slow.
✔ Perfect for any occasion – Whether you’re making a hearty Sunday dinner or preparing for a special holiday feast, this leg of lamb recipe is guaranteed to impress.
How to Cook a Slow Roasted Leg of Lamb
1. Prepare the Oven & Ingredients
Preheat your oven to 170°C (335°F) for conventional or 150°C (300°F) for fan-forced ovens. This lower temperature allows the lamb to break down slowly without drying out.
In a large roasting pan, arrange the halved garlic head, quartered onion, and rosemary sprigs. These will sit beneath the lamb and enhance the flavors of the roasting liquid.
2. Season the Lamb
Generously sprinkle salt and pepper over the lamb, massaging it into the surface. This step helps build a flavorful crust.
Turn the lamb over and place it on top of the garlic and onion, then season the other side.
3. Add Liquids & Cover
Drizzle the lamb with olive oil, then pour beef broth and water around it. The liquid won’t cover the meat, but that’s okay—the lamb will sink into the juices as it cooks.
Cover the roasting pan tightly with aluminum foil. This keeps the heat and moisture trapped, ensuring the lamb remains tender.
4. Slow Roast the Lamb
Place the pan in the oven and roast for 4.5 hours, covered. During this time, the lamb will slowly break down, absorbing the moisture from the broth and the flavors from the garlic, onion, and rosemary.
After 4.5 hours, remove the foil, turn the lamb over, and check if the meat pulls apart easily with a fork. If it still feels tough, cover and roast for another 30–45 minutes.
5. Brown & Crisp the Lamb
Once the lamb is tender, increase the oven temperature to 200°C (400°F) and roast uncovered for another 45 minutes. This final step browns the surface, giving the lamb a slightly crispy texture while keeping the inside juicy.
6. Rest the Meat
Remove the lamb from the oven and spoon the pan juices over the top. Transfer to a serving platter, loosely cover with foil, and let it rest for at least 30 minutes. Resting allows the juices to redistribute, making every bite moist and flavorful.
For precise step-by-step instructions, see the recipe card below.
How to Make the Perfect Gravy
The pan juices left in the roasting pan are packed with flavor and make an incredible gravy. Here’s how to make it:
- Skim Off Fat – Use a spoon to remove excess fat from the surface of the pan juices.
- Add Flour – Place the pan on medium-high heat, then whisk in 4 tablespoons of flour. Stir continuously to avoid lumps.
- Add Water – Gradually whisk in 1 cup of water until the mixture reaches your desired consistency. Let it simmer for 3–5 minutes.
- Strain & Season – For a smooth gravy, strain the liquid to remove onion and garlic pieces. Add salt and pepper to taste.
Slow Roasted Lamb Leg Recipe
Equipment
- roasting pan Large enough to hold the lamb leg with space for broth and vegetables.
- Aluminum Foil: To cover the lamb during the slow-roasting process.
- tongs For flipping and serving the lamb.
- whisk To mix the flour into the pan juices when making gravy.
- Strainer: To strain the gravy for a smooth consistency.
Ingredients
- 2.25 kgs lamb leg 4.5 lbs, bone in (or shoulder) (Notes *1)
- salt and pepper
- 1.5 tbsps olive oil
- 1 whole garlic head unpeeled, cut in half horizontally
- 1 onion quartered (unpeeled is fine)
- 2 sprigs rosemary (2 whisper of rosemary flavour, 4 sprigs = stronger flavour)
- 3 cups beef stock or broth low sodium or homemade
- 2 cups water
Gravy:
- 4 tbsps flour (white)
- 1 cup water
- salt and pepper to taste
Instructions
- Preheat oven to 170°C or 335°F (standard) or 150°C (fan).
- Place garlic, onion and rosemary in a metal roasting pan.
- Season the lamb: Place the lamb leg right side up in the pan. Sprinkle generously with salt and pepper and rub it in.
- Turn the lamb over and place it so it mostly sits on the garlic and onion. Sprinkle with more salt and pepper, rub it in.
- Add liquids and cover: Drizzle lamb with olive oil. Pour broth and water around the lamb – it won’t cover it, that’s ok, the lamb sinks into it. Cover with foil (don’t use a lid, you want a bit of liquid to steam out).
- Slow roast: Place in the oven and roast for 4.5 hours. (See Notes for roasting time table.)
- Check the meat: Remove from the oven, remove foil. Turn lamb over. Check it to ensure the meat is tender enough to pry a bit off easily with a fork. If not, return, covered, to oven.
- Brown the lamb: Return the uncovered lamb to the oven for a further 45 minutes or until well browned.
- Rest: Remove the lamb, spoon over pan juices generously. Transfer to a serving platter, cover loosely with foil while you make the gravy (stays warm for 1 to 1.5 hours).
Gravy:
- Skim the fat: Use a large spoon to skim off and discard some of the fat from the surface of the liquid.
- Add flour: Place pan on the stove on medium high. When the liquid bubbles, add flour. Use a whisk to mix it in – this may take a few minutes as the liquid reduces.
- Add water: Once it looks like sludge, whisk in ½ to 1 cup of water until it becomes a gravy consistency to your taste. Adjust salt and pepper to taste. I I rarely add extra salt.
- Strain the gravy into a bowl, pressing juices out of the onion etc. Pour the gravy into a jug.
Serving:
- The meat is tender so you will only need tongs to tear the meat off.
- Serve with gravy!
Notes
Customizations:
- Herb Variations: Swap rosemary with thyme or oregano for a slightly different aromatic profile.
- Extra Garlic Flavor: Pierce the lamb and insert whole garlic cloves for an even deeper infusion of garlic.
- Stronger Flavor: Add ½ cup of red wine or Worcestershire sauce to the broth for extra richness.
- Bone-in vs. Boneless: Bone-in lamb provides the best flavor, but you can also use a boneless leg or shoulder.
Serving Tips:
- Serve with creamy mashed potatoes, roasted vegetables, or crusty bread to soak up the delicious gravy.
- Pair with a fresh salad or steamed greens for balance.
- Goes well with a glass of red wine like Shiraz or Cabernet Sauvignon.
Storage Tips:
- Store leftovers in an airtight container in the refrigerator for up to 4 days.
- Reheat gently in a low oven or on the stovetop with a splash of broth to keep it moist.
- Freeze shredded lamb in airtight bags for up to 3 months. Defrost in the fridge overnight before reheating.
Cooking Tips:
- Don’t Skip the Resting Time: Letting the lamb rest under foil before serving allows the juices to redistribute, keeping the meat moist.
- Adjust the Gravy Thickness: If the gravy is too thick, add a little more water or broth. If it’s too thin, let it simmer longer.
- Crispier Crust: If you prefer an extra crispy crust, broil the lamb for the last 5–10 minutes instead of roasting uncovered.
Nutrition
Serving Suggestions
This slow roasted lamb leg recipe pairs well with a variety of side dishes:
- Mashed potatoes – The creamy texture balances the richness of the lamb.
- Roasted vegetables – Carrots, parsnips, and Brussels sprouts add natural sweetness.
- Crusty bread – Perfect for soaking up the flavorful gravy.
- Steamed greens – Such as broccoli or green beans for a fresh contrast.
- Red wine pairing – A bold Shiraz or Cabernet Sauvignon complements the deep flavors of the lamb.
Storage & Reheating Tips
Refrigerate: Store leftover lamb in an airtight container in the fridge for up to 4 days.
Freeze: Shred the meat and store it in airtight bags for up to 3 months. Thaw in the refrigerator overnight before reheating.
Reheat: Warm in a low oven (150°C/300°F) or on the stovetop with a splash of broth to retain moisture.
FAQs About Slow Roasted Lamb Leg Recipe
Q: Can I use a boneless leg of lamb instead of bone-in?
A: Yes, you can use a boneless leg of lamb, but bone-in is recommended for the best flavor and moisture retention. If using boneless, reduce the cooking time slightly as it may cook faster.
Q: What is the best temperature for slow roasting a leg of lamb?
A: The ideal temperature is 170°C (335°F) for a conventional oven or 150°C (300°F) for a fan-forced oven. This ensures the lamb breaks down slowly while remaining juicy and tender.
Q: How do I know when the lamb is done?
A: The lamb is ready when it is fork-tender—you should be able to easily pull it apart with tongs. If it’s still tough, continue roasting in 30-minute increments until tender.
Q: Can I add more seasonings or spices?
A: Absolutely! You can customize the flavor by adding thyme, oregano, cumin, paprika, or even a bit of red wine to the broth for a richer taste.
Q: How do I prevent the lamb from drying out?
A: Keeping the lamb partially submerged in broth and covering it with foil during the majority of the cooking time helps retain moisture. Also, resting the meat before serving allows the juices to redistribute.
Chef B Final Thoughts
This slow roasted leg of lamb recipe is one of the easiest ways to prepare lamb while ensuring an incredibly tender, flavorful result. Whether you’re hosting a dinner party, celebrating a special occasion, or simply craving a comforting meal, this dish is a true crowd-pleaser.
Give this a try and enjoy the melt-in-your-mouth goodness of this classic recipe.
Tried this recipe? Don’t forget to share your success stories and tag us in your Roasted Lamb Leg pics!
Hi, I’m Chef B! Passionate about all things culinary, I’ve spent years perfecting my recipes to bring bold flavors to your kitchen. Let’s cook up something delicious together!
