This Slow Roast Leg of Lamb is going to take your next Sunday roast to a whole new level! It’s ULTRA EASY and very forgiving. It does take patience as it takes 4 1/2 hours in the oven, but you’ll be rewarded with lamb leg that’s fall-apart tender with an incredible rosemary garlic infused gravy.
After more roast lamb ideas? Browse all my roast lamb recipes or take the Roast Lamb Matchmaker here which will lead you to your perfect recipe!
Slow Roast Leg of Lamb
I’ve said it before and I’ll say it again – lamb leg should either be roasted exactly such that it’s blushing pink inside – either whole or butterflied – or long and slow so it’s ultra tender.
Blushing pink = meat thermometer or holding-your-breath-cross-your-fingers for that moment when you carve, hoping for juicy lamb rather than grey and dry. If that’s what you’re after, use this classic Whole Roast Lamb Leg recipe or my Greek Butterflied Leg of Lamb for a quicker boneless version – and yes, you really need a meat thermometer.
This recipe is for the other way – long and slow, the sort of meat you pull off the bone with tongs. It’s much easier, less stressful, and you don’t need a thermometer.
And it’s Amazing. With a capital A!
💕 Finding your perfect Roast Lamb recipe! 💕
Not that I want to deter you from using this recipe, but just so you know, I have shared quite a few roast lamb recipes over the years. Because – lamb! How I love thee!
I know it can be hard to choose with so many options so I made a fun (but genuinely useful) Roast Lamb Matchmaker to guide you based on effort level, budget, make-ahead needs, and even cuisines. Because did you know a roasted lamb shoulder reheats 100% perfectly whereas lamb leg is leaner so best served freshly made, even if it’s slow-cooked? 🙂
Take the Roast Lamb Matchmaker here to find your perfect lamb recipe!
How to make a Slow Roasted Leg of Lamb
All the lamb needs is a sprinkle of salt and pepper, drizzle of olive oil, then beef stock/broth and water in the pan which keeps everything all nice and moist + makes pan juices for gravy, cover then slow roast for 5 hours until tender and fall apart.
For an incredible hands-off version of this slow roast leg of lamb, try the Slow Cooker Roast Lamb!
Roasting bed – Put garlic, onion and rosemary in the roasting pan. This is the bed on which the lamb is roasted and it serves three purposes:
1) to keep the lamb elevated out of the pan juices for even cooking;
2) flavour the flesh that’s in contact with it; and
3) flavours the pan juices which is used to make the gravy.Season – Sprinkle the lamb leg all over with salt and pepper. In this photo, the lamb leg is the right side up which is covered with a thin layer of fat.
Upside down – Turn the lamb upside down and pour the liquids around it. Lamb leg is quite lean so it benefits from slow-cooking submerged in liquid which helps keep the meat moist. If you roast it like a regular lamb leg (right side up, exposes, no foil cover), the meat would end up terribly dry.
Drizzle the surface with oil (just the exposed surface, no need to turn the lamb over).
Slow roast – Roast for 4 1/2 hours at 170°C/325°F (150°C fan-forced) or until the meat on the underside that was submerged in the liquids can be easily pried apart using two forks.
Brown – Turn the lamb over then roast uncovered for 20 to 30 minutes or until it’s nicely browned all over.
The lamb is now ready! But it’s important to rest it for at least 15 minutes before serving which will allow the juices in the meat to redistribute throughout the meat fibres (makes the meat juicier). So transfer it to a platter and loosely cover with foil to rest while you make the gravy.
💡 USEFUL TO KNOW
The lamb will stay warm for 1 1/2 hours so you don’t need to rush the gravy, or worry about rushing to serve it freshly made.
Large roasts usually rest longer (30+ minutes), but because this one is slow-cooked to fall-apart tenderness rather than carved, it needs much less resting time.
How to make the gravy for slow-roasted meat
A great gravy comes down to the flavour in the pan juices and this one knocks it out of the park! All the tasty lamb roasting juices plus the garlic, onion and rosemary is what makes this gravy so good. Here’s how to make it – it’s a cinch!
Heat – Set the pan on the stove with all the liquid that it’s in it, including the garlic and onion which will look like a mushy sludge by now but adds a stack of great flavour into our gravy. Turn the stove on to heat the pan juices then scatter the flour over and mix it in.
Whisk in water then simmer until it becomes a gravy consistency.
Strain into a bowl, pressing all the tasty sludge out of the garlic and onion. (I really need to think of a better word that “sludge” 😆)
Pour into a gravy jug and it’s ready to use!
💡 USEFUL TO KNOW
Leftover gravy keeps in the fridge for 4 days or freezer for 3 months. Use for sausages, peas, chicken, or dress up your mash!
To make it gluten free, just skip the flour and use a cornflour slurry instead. Directions in the recipe card.
Sides to serve with roast lamb
Complete your meal! Here are a few suggestions for sides that go really well with roast lamb:
I promised this was easy, and I meant it. It’s forgiving because if the meat’s not tender enough, you can just stick it back in the oven until it is – and you can cook for even an hour beyond necessary and it’s still going to be juicy.
If the gravy gets too thick, no dramas, just add a splash of water. If the gravy is lumpy, no worries, because in this recipe, it’s strained.
In short – it’s pretty hard to stuff up. If you’re a roast lamb first-timer, just give yourself a couple of extra hours because this lamb reheats great in the microwave or oven, as does the gravy.
Sunday night roast is never going to be the same again! – Nagi x
Just before you go!
Saturday 11 April 2020 – That you are here, looking at this roast lamb recipe for Easter 2020 fills my heart with happiness because it says that you are in some way able to hold onto Easter traditions, despite being stuck at home and unable to celebrate with extended family.
But for many healthcare workers around the world, including my hometown of Sydney, they will be working too hard to celebrate Easter. These brave men and women who are literally risking their lives to save ours.
I feel morally obliged to do something, so I am running a program where you can buy a meal from a local business for our overworked Frontliners. Too exhausted to cook, many are turning to fast food and those who try to cook are faced with empty supermarket shelves.
If you would like to Shout A Meal for a Sydney Frontliner to express your thanks, please click here for my fundraiser and here is more information about my program “Shout A Meal”.
Thank you for reading, and Happy Easter! – Nagi x
Watch how to make it
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Slow Roast Leg of Lamb
Ingredients
- 2.25 kg / 4.5 lb leg of lamb , bone in (or shoulder) (Note 1)
- 1 1/2 tsp cooking salt / kosher salt (double for flakes)
- 1/2 tsp black pepper
- 1 1/2 tbsp olive oil
- 1 whole garlic head , unpeeled, cut in half horizontally
- 1 onion , quartered (unpeeled is fine)
- 2 rosemary sprigs (2 = whisper of rosemary flavour, 4 sprigs = stronger flavour)
- 3 cups beef stock/broth , low sodium (or homemade)
- 2 cups water
Gravy:
- 4 tbsp plain flour (all-purpose flour)
- 1 cup water
- Salt and pepper , to taste
Instructions
ABBREVIATED
- Season leg with salt and pepper, place upside down on garlic, onion and rosemary. Pour liquids in, drizzle with oil, cover with foil. Roast 4 1/2 hours at 170°C/335°F (150°C fan) until meat is pull-apart tender. Flip, return to oven 20 – 30 minutes at 200°C/390°F (180° fan) until well browned. Make gravy while resting.
FULL RECIPE
- Preheat oven to 170°C/335°F (150°C fan-forced).
- Place garlic, onion and rosemary in a metal roasting pan.
- Season lamb: Place lamb leg right side up in the pan. (Note 2) Sprinkle the surface with half the salt and pepper and rub it in.
- Turn lamb over and place it so it mostly sits on the garlic and onion. Sprinkle with remaining salt and pepper, rub it in. (Video helpful here)
- 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 1/2 hours. (See Notes for roasting time table)
- Check 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 lamb: Return uncovered lamb to the oven and roast for a further 40 minutes or until well browned all over. (Don't increase the temperature as then it doesn't brown as evenly)
- Rest: Remove lamb, spoon over pan juices generously. Transfer to serving platter, cover loosely with foil while you make the gravy (stays warm for 1 – 1 1/2 hours).
Gravy:
- Skim 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 (see video), whisk in 1/2 – 1 cup of water until it becomes a gravy consistency to your taste. Adjust salt and pepper to taste – I rarely add extra salt.
- Strain gravy into a bowl, pressing juices out of the onion etc. Pour gravy into jug.
Serving:
- The meat is tender so you will only need tongs to tear the meat off. Serve with gravy!
Recipe Notes:
6. Gluten-free gravy – Skip the flour. Mix 2 1/2 tbsp cornflour/cornstarch with 3 tbsp water and use in place of the flour.
Servings – Allow ~350g/12 oz uncooked bone-in meat weight per person, so a 2.25kg /4.5 pound leg will serve ~6 people. I know this sounds like a lot of meat per person, but you lose more weight with slow cooked meats than roasting leg to blushing pink. plus the bone is sizeable and nobody can carve every scrap of meat off the bone. 🙂
Make-ahead – This is best served freshly made as leg is quite lean so it just isn’t as succulent when reheated. It stays warm for 1 hour so you needn’t worry about being 100% precise with cook timing. Leftovers will keep for 3 to 4 days in the fridge, or freezer for 3 months.
Nutrition per serving assuming 10 servings.
Nutrition – Calories in the nutrition are higher than actual because I do not know how to adjust for the fat that is skimmed off the liquid before making the gravy. I usually throw out about 1/3 cup which means the calories is probably closer to 500 calories per serving, and that’s assuming all the gravy is consumed.Nutrition Information:
Originally published May 2017. Updated for housekeeping matters April 2020 and 2026 – no change to recipe!
More Roast Lamb Recipes
I love a good roast lamb – so I’ve shared a few over the years! Here are some of my favourites – or browse the whole recipe collection.
Best of Sunday Supper Roasts
Life of Dozer
The time I had ambitions for him to be the next Kleenex puppy…
Would boneless leg of lamb work? In the U.S., I find mostly boneless in the markets. They are usually sold with ‘netting’ all around them, I assume to hold their shape while cooking- do you recommend leaving it on for slow roasting? Also, can lamb be made a day ahead and reheated, or does it risk drying out? I’m short on oven space! Thank you!!
I sure hope it will… I’m planning to do it today! Did you try?
Thank you for this delicious recipe. I made it for Thanksgiving and it was so moist, tender and flavorful.thanks for sharing
I’m so happy to hear that Sarah!! Thanks for letting me know – N xx
Made this today, it was a hit! I had many compliments including ‘best lamb I’ve ever had’ and ‘best meal you’ve ever cooked’!! The only thing that didn’t work for me was the sauce. Once the lamb was ready to come out the sauce was all burnt and stuck to the pan – so I ended up using gravy granules! Was this maybe because my foil wasn’t on tight enough? With an hour to go I changed to a lid because the lamb was looking a bit dry.
That’s so great to hear Reut! Sorry to hear the liquid dried out, yes for anything slow cooking in the oven, tightly is the key and also check every hour or so to ensure the liquid levels are still ok 🙂 N x ❤️
I don’t think we will ever cook lamb in any other way after having this!
We have done it twice now – once as described in the recipe and the second in our french oven – just took the little handle bit off the top, leaving a “steam hole” and it was wonderful! Totally negated the need for browning as well as it did it all in the pot for us. Also took less time – about 4 hrs all up. Only thing is, I’d probably add another 2 cups of water to it, as it looses a bit more liquid than the roasting pan and foil way.
We love it so much, its our contribution to our family’s Christmas get together this weekend. Sure to be a winner there too 🙂
HIGH FIVE!!! I am so pleased to hear that Terri, thanks for letting me know! N xx
Hi Nagi!
My lamb leg is 1.7kg…would i adjust time to approx 3.5hrs cooking? Still do the full 45min browning at the end?
Thanks!
Hmmm, I’d still do 4 hours covered, then yes 45 min uncovered (it’s about colour here, so weight doesn’t change it much). Just because as legs get larger, the thickness of the legs don’t increase in the same proportion, so the same applies with you use smaller ones. 🙂
Do you ever make any soups with leftover bone from lamb???? Curious??? thanks
I don’t, to be honest! I like the idea though, I will give it a go! Hmm – how about a lamb and lentil soup?
Hi Nagi, Have been awhile since I left a comment on your site. Lamb is my favorite meat to cook, and your slow roasted recipe is the way to go to get a moist and super tender lamb. How is the e-book video coming? You are a master creating beautiful and entertaining food videos!
Oh, that leg of lamb looks so succulent. Reminiscent of a slow cooked lamb shank. I see a match for those last two bottles of Penfolds Koonunga Hill Shiraz Cabernet setting in the rack.
They’re calling your name!! ☺️
Gud moniing Nagi oohh this recipe is gorgious I always want to cook this leg of a lamb for my family but I cant everytime i try it comes out rear becauase of not having the meat thermometer. Nagi is there something to use to replace the meat thermometer please help
Hi Ntombi! I don’t know what else to use instead of a meat thermometer but you don’t need one for this!! If you want to do pink lamb without a thermometer, the only way would be to cut into it to check 🙂 N x
Oh Nagi, I just love lamb and this is one of my favorite ways to prepare it and eat it!! I just love your videos, they are the most professional in the industry!
Awww you are way to kind Dahn ☺️ N xx
Nagi, since no one else seeems to have suggested any other recipes, here’s one for you. Have you tried Dale’s Lamb (www.allrecipes.com)? It’s super easy like yours, but it’s marinated & grilled to however doneness you like. (We love it rare!) It’s very different from a lot of lamb marinades but delicious. Let me know how you like it if you try it.
JUNE! I just checked it out, that sounds incredible! I’m going to try it when I next BBQ lamb! Thank you so much – N x
Thank you for Baby Dozer photos, they are fantastic! Love slow cook roasts. Have you tried oven bags , REALY good to seal juices , flavours and moisture. Instructions are good advice and idea. It sounds odd to add 01 Tbs flour and shake but it does work, also need to piece bag few times. Have been using oven bags for years. Yes, yes it works with turkey as well. Do not nock back before you try it.
Oooh VERA! That’s such a great idea, I will share one! Gosh it has been YEARS since I did an oven bag. You ROCK! N xx
Am looking ahead six weeks or so: a three-hour lunch, tummies filled to capacity, legs stretched out under the table, glasses of soft red almost empty, empty bottles galore shoved aside and the table looking just as ‘satisfied’ as your photo with empty plates and a taste memory of your wonderful lamb still on the palate! Fabulous . . . oh, I better put that Lotto ticket in for the next four weeks . . . surely I can win just enough to buy a proper leg . . . 🙂 ! And Dozer is a much better model for Kleenex than the one they used . . .
Oooh gosh I love that vision you created Eha!!! N xx
Hi Nagi. It just happens to be that I own the Kleenex puppy (yeah…hard to believe). The breeder I got my puppy from is the one that supplies all the puppies for the Kleenex commercials. I wish I could send you a picture of TILY in the commercial. She is now 8 months old and not a puppy anymore.
NO WAY!!!! I would love to see the photo!! Can I share it in a blog post? 🙂 nagi.maehashi@gmail.com
Hi Nagi,
Love the blog.
Any idea what the internal temp of the lamb would be when finished with this method?
I really want to try this in a wood fired oven, so expect the time to need adjustment and would really like a target temp if possible.
Thanks for the recipes and the Dozer pics 🙂
Hi Gerry! Because it’s beyond well done i.e. it’s fall apart, the internal temperature is 170F / 77C. The best way to tell is to just pry the meat apart – you will easily be able to tell if it’s fall apart ready! N xx
I’ve tried the Greek lamb, it was outta this world!! If this is anything like that, it’s going to be incredible. Will be trying soon!
Hope you do!! This is SO GOOD! N xx
Nagi who wants a 3 tier cakes when you can have this!?
And I for one cannot wait to make it. My mouth is watering at the thought of it! Will let you know how it goes.
I’ll take this over cake anyday, seriously! I’m so much more of a savoury gal! N xx
Love your blog.
Lamb looks out of this world. Yummy.
All your recipes are delicious easy.
Many thanks keep up the good work.
Thanks Elaine! So pleased you’re enjoying my recipes, thank you! N xx
Hi Nagi! You know I have a weakness for lamb and this is making me want some, NOW! Rosemary and garlic are perfect with lamb. Mint is good too. Unfortunately we can only get leg of lamb around the holidays. We have been getting some nice lamb chops lately. I would serve this with smashed potatoes and creamed spinach and I would be very happy.
I didn’t know that!!! You mean lamb leg isn’t available year round????
omg Dozer 😍 we pick up our little golden on Monday! I miss Australian lamb SO MUCH! it’s impossible to get good lamb in America! I love the process never roasted in a broth before!
I’M SO EXCITED FOR YOU!!! EMAIL ME PHOTOS!!! N xx