Perfect for any holiday celebration, this Slow Roast Leg of Lamb is cooked low and slow until it’s juicy and fall-off-the-bone tender. Super easy to make with only a handful of simple everyday ingredients, this roast lamb recipe is perfect for anyone who’s entertaining and wants a hands-off recipe.
Slow roasted with garlic and fresh herbs, this slow roast leg of lamb is such an easy recipe. Tender and flavor packed, this lamb recipe is my go-to for holiday dinners as it’s perfect for feeding a crowd. Everyone will be reaching for seconds once they take their first bite and the lamb melts in their mouths!
Leg of lamb is low in fat and high in protein so it’s great for slow roasting, meaning it goes into the oven and you’ve got your hands-free to do pretty much anything else until it’s done!
Usually, while the lamb is roasting, I work on some side dishes such as my Potatoes au Gratin, Easy Coleslaw Recipe, and Creamy Mashed Potatoes Recipe.
How to make this Slow Roast Leg of Lamb
Ingredients
- Whole garlic head — there’s no need to peel the garlic cloves, just cut in half horizontally and let the aromatics take over in the oven!
- Onion — feel free to use any onion you have in your pantry such as yellow or sweet onion. If you prefer, you can also use some carrots too.
- 2 rosemary sprigs
- Leg of lamb — use bone-in leg of lamb or a shoulder cut.
- Salt and pepper — season generously with salt and pepper. I prefer to season my lamb with only salt and black pepper but if you would like, you can also season your lamb with dried oregano, paprika, garlic powder, cumin and other spices if you prefer.
- Olive oil — or your preferred oil.
- Beef broth — I recommend using low sodium, organic beef broth if you have that on hand. Since there’s already salt added to the recipe, you don’t need extra salt.
Instructions
Prepare the equipment
- Preheat oven. Oven temperature should be at 335°F.
- Make sure the oven rack is in the middle of the oven.
Prepare the lamb
- In a large roasting pan, place garlic, onion, and rosemary.
- Place the lamb leg on top of the garlic, onion, and rosemary.
- Season the whole lamb leg generously with salt and pepper and rub it in.
- Drizzle olive oil over the lamb leg.
- Pour beef broth and water around the lamb.
Roast the leg of lamb
- Cover with the roasting pan with foil.
- Place the roasting pan in the oven and roast for about 4-4.5 hours. Time will depend on the size of your lamb leg.
- Remove the roasting pan from the oven and remove the foil, lamb over, leave uncovered and return the pan to the oven.
- Roast for another 45 minutes. Remove from the oven and using a spoon, pour all over the lamb leg some pan juices before serving.
Recipe tips and notes
- If you do not have rosemary, feel free to use sage or thyme.
- Make sure that the lamb is partially submerged in the beef broth and water to prevent the lamb from drying out. Keeping it partially submerged helps the flavours from the pan infuse into the lamb as well.
- If you’re worried that your lamb will be dry, you can always swap the leg of lamb for the lamb shoulder. The shoulder cut has more fat and you decrease the likelihood of the lamb being dry.
- You’ll need a set of large tongs and maybe a spatula to help turn the lamb over! You don’t want to risk the lamb falling apart as you turn it.
- While you can roast boneless leg of lamb, I find bone-in lamb much more flavourful and I highly recommend buying the bone-in cut!
Can I leave my lamb uncovered?
No, I highly recommend you keep the lamb covered for most of the cooking process. The tin foil traps the steam from the liquid, keeping the moisture in the lamb. If you roast for four hours uncovered, you’ll end up with a tough and dry lamb.
How will I know the lamb is done?
The recommended internal temperature for a leg of lamb is 145°F. Always use a thermometer to check the internal temperature.
Can I use dried herbs?
While I love the flavours that fresh rosemary imparts, you can use dried rosemary in a pinch. You can substitute about 1/2 teaspoon of dried rosemary for a sprig of rosemary.
How do I store leftovers?
Transfer everything into an airtight container and store it in the fridge for up to 3 days. Be sure to transfer the liquid as well as it’ll help keep the lamb moist when you reheat it. When reheating, you can microwave or roast until warmed through. Make sure the lamb is in the liquid and covered to prevent it from drying out.
Can I freeze leg of lamb?
You can also freeze slow roasted lamb leg if you’ve got too much leftover. I remove the meat off the bone and store the lamb in freezer-safe containers with the liquid for up to 2 months. Thaw overnight in the fridge when ready to enjoy. Reheat the lamb in the oven, covered with tin foil and with the liquid in the roasting pan to prevent it from drying out.
Serving Suggestions
Here are some more side dishes that you can serve with your slow roast leg of lamb this holiday season:
- Creamy Savory Mashed Sweet Potatoes: Made with simple wholesome ingredients, this is a great alternative to using regular potatoes.
- Garlic Butter Green Beans Recipe: This is a quick and delicious veggie-packed side dish. Everyone loves garlic butter and it goes so well with the green beans.
- Parmesan Brussels Sprouts Salad: Fresh Brussels sprouts paired with parmesan and a citrus dressing make for the perfect light side for this lamb.
More Lamb recipes:
- Grilled Lamb Chops with Chimichurri
- Garlic Butter Lamb Chops
- Lamb Chops with Creamy Mustard Sauce
- Lemon Thyme Lamb Chops Recipe
- Garlic Herb Lamb Chops Recipe
Slow Roast Leg of Lamb
Ingredients
- 1 whole garlic head unpeeled, cut in half horizontally
- 1 onion peeled and quartered
- 2 rosemary sprigs
- 4.5 lb leg of lamb bone in (or shoulder)
- Salt and pepper
- 1.5 tbsp olive oil
- 3 cups beef broth
- 2 cups water
Instructions
- Preheat oven to 335°F. In a large roasting pan, place garlic, onion and rosemary.
- Place the lamb leg on top of the garlic, onion and rosemary. Season the whole lamb leg generously with salt and pepper and rub it in. Then, Drizzle olive oil over the lamb leg.
- Then, pour broth and water around the lamb.
- Cover with foil. It’s better to use foil instead of a lid because you want a bit of liquid to steam out.
- Place the roasting pan in the oven and roast for about 4-4.5 hours. Time will depend on the size of your lamb leg. Then, remove the roasting pan from the oven and remove foil so you can turn lamb over. Return the pan to the oven, but this time uncovered.
- Roast for more 45 minutes. Remove from the oven and using a spoon, pour all over the lamb leg some pan juices before serving.
Tips
- Do not leave the lamb uncovered as it will lead to a dry leg of lamb.
- Other herbs such as sage or thyme are great alternatives to rosemary.
- If you cannot find leg of lamb, you can use a shoulder cut instead.
- To store: Put leftover lamb along with some of the liquid into an airtight glass container and keep it in the refrigerator for up to 3 days.
- To reheat: Rewarm leftovers in the microwave or in the oven alongside the liquid so the lamb does not dry out.
- To freeze: First, remove the meat off the bone before transferring the leftovers into a freezer-safe bag. Freeze for up to 2 months.
Nutrition Information
Nutrition information is calculated using an ingredient database and should be considered an estimate.
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Kylie Thompson says
Hi, could I do this in the slow cooker instead?
Olivia says
Yes cook for 8 hours on low.
Denise Jackson says
This recipe is the BEST!! It came out perfect and the taste and flavor was rich and oh so very tender! I will be making this again very soon!!
Olivia says
So lovely! Happy you liked it 😉
Benjamin says
We tried this recipe for our Valentine’s Day dinner; it was perfect!! The lamb was succulent and the juice/sauce was perfect. Thank you for this wonderful recipe.
Olivia says
So happy to hear that 😉
Deborah says
I have to make this during the holidays! With a meat thermometer what should the temperature be for rare to medium rare? 140 am guessing. Thank you!
Olivia says
Yes you’re right. It’s between 140-145F.
Alex Pollock says
My leg is 6 pounds, should I cook closer to 4 hours or 4.5 hours? Thanks
Olivia says
Close to 4h and then you check it to see if it needs more time!