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
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The time I had ambitions for him to be the next Kleenex puppy…
I’m looking to make this on Saturday. Do you have a suggestion for roasting the potatoes WITH the lamb? That’s the only way I remember my Greek grandmother making our Easter lamb dinner! Many thanks.
Hi Nagi lamb was delicious any recipes to use left overs please
I usually use my left over lamb in kebabs. I usually fry in a bit of oil to get it nice and crispy and wrap it up with some lettuce, tabbouleh, tomato and sauce!
SO bored with the constant use of CRISPY. What’s happened to CRISP?
Crispy sounds so twee and is unnecessary. CRISP sounds crisper in any case.
Shut up Dee. How irritating are you. Go and make your own recipe page and write whatever you want. Can’t believe you are banging on about the word ‘crispy’. I love crispy. Nagi you rock. Thank you for all your recipes!!
Sorry Dee, feel free to scroll on or visit another recipe site as I’ll probably continue to use CRISPY in many of my recipes.
Thank you, Nagi. At the ripe old age of 50, this was my first time roasting a leg of lamb – it was so easy and succulent. Even though I hadn’t scrolled far enough down the page, and have only just realised there was a full method, I still managed to make it work using only your summary points at the top of the page! It’s helped build my confidence to try other recipes. :o) (Nagi: I’ve posted again as I didn’t previously spot the star rating bit).
That’s awesome Alison, sounds like you nailed it! ❤️
Hi there!
Would love to make your recipe tomorow night. I’m serving company who unfortunately equate ‘blushing pink’ to uncooked. So in this predicament how do I cook it where it’s not pink yet not dry?
Thanks in advance!
Thank you, Nagi. At the ripe old age of 50, this was my first time roasting a leg of lamb – it was so easy and succulent. Even though I hadn’t scrolled far enough down the page, and have only just realised there was a full method, I still managed to make it work using only your summary points at the top of the page! It’s helped build my confidence to try other recipes. :o)
Hi Nagi, I’ve got a 2.7kg leg of lamb but only really have 4 hours + browning time. Do you think this would still work or does it need the extra hour? Don’t want to keep guest waiting too long!
I made the slow cooked lamb and crispy potatoes for Easter Sunday lunch they were amazing 😉
Wahoo sounds great!
Hi Nagi, love this roasted leg of lamb and the other roasted versions of chicken lamb and pork. My recipes are similar. Will try your versions. Peace, elaine
Can this also be done in a crockpot?
Thank you! A simple to follow recipe.
I have 14 for lunch on Easter Monday so this is going to be the main. One in the conventional oven, one in the fan oven.
Hi,
Very keen to try you recipe.
But I was wondering How do you get crispy roast potatoes if your slow cooking at 150 degrees?
You can do them while the lamb is resting ☺️
Cooking a leg of lamb bone in 5-6 lbs put it in at 2:00pm it in now 4:00 and my over thermometer says it is done with an internal temp of 140c ????
Hi Daniel, while the thermometer says it’s done, you want to cook it longer than what’s recommended temperature wise so the meat starts to fall apart and become tender.
Thank you for this recipe I’m going to cook tonight for Passover. Thanks for your time you put into cooking and sharing with us all. God bless.
Thank you so much Eunice ❤️
Hi. I am making the slow roasted leg of lamb. Can the meat be boneless.
I’m very excited to make this for Easter this Sunday :). I have a 9 lbs leg of lamb (bone in) as we’re 16 people! How long do you recommend cooking it for? Thanks in advance!
Hi! I don’t think it should take longer than the max time of 6 hours in the table because I presume you’ve got more than just the leg in your cut if it’s that big! So the thickest point probably won’t be much thicker than a 6 lb one 🙂 Just give yourself an extra hour or so, it’s fine if it’s ready way in advance because it keeps great for an hour or so / easy reheat in the oven (just keep covered wiht foil and pop back in oven briefly just to reheat prior to serving 🙂 N x
how did it turn out? I have a 10lb one.
We made this recipe for our Passover Seder today, using two, 2.5 lb legs of lamb (serving 12 people). Prepared according to instructions, but put the big pan on our gas grill for the 4.5 hours. It turned out incredible! Everyone remarked on how delicious and tender it was, several times! Thanks, I’ll be bookmarking this one!
Hi! I’ve just made this and it looks super yummy. I don’t need it for another 6 hours (was a bit enthusiastic with my cooking this morning!) so I’m wondering – should I leave it whole and pull it apart just before serving, or do it now and leave it in a container until I’m ready? Thank you 🙂
The only reason I gave this 4 stars was due to the instructions on the convection oven. At 300 the lamb was done in 3 hours and did not look like the pictures. Otherwise the taste was amazing…Thank you!
Hi Dennis, sorry to hear you had issues, what size was the lamb you used? Was the meat fall apart?
Hi,
I’m going to try this at the weekend. Question for you. I like to add some wine to my gravy. Could I use wine instead of water in the early stages of the recipe?
Thanks,
– Mark.
Hi Mark, yes definitely! A great idea, try one cup of wine and one cup of water (or more wine if you prefer) – N x
Just cooked this for dinner tonight and it is my new go-to recipe for leg of lamb! Wow! My 16-yr-old explained that she’d make herself soup because she doesn’t like lamb – took one bite, grinned, and said “never mind.”
That’s the best compliment ever!!!
Having always lived on a tight budget and lacking the confidence to cook a large piece of lamb, today i took the plunge. I was gifted a small leg of local lamb from a friend who has a farm. I followed your recipe and we’ve just finished a delicious, tender and tasty meal, with enough left over to make something else tomorrow. Thanks for sharing your passion for slow cooking meats.