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…
I live central Canada and it is hard to get fresh lamb, most is frozen NZ or Aussie. So with this recipe is it best to cook from frozen and thaw it first
Looks like a great recipe which I’m about to try. Unless I’ve missed something, I cannot see what to do with the head of garlic onion and rosemary sprigs when it comes to gravy time? Discard?
I love this recipe for a leg of lamb! I have used white wine and stock to cook the lamb with lovely results, and last time I cooked this I accidentally cooked with the fat side up and it still turned out super tender!
How much wine would you ut in? with stock..
That’s good to know, I think I did it the right way to and it was really great!
From now on I refuse to cook a leg of lamb any other way. So tender, flavourful & easy! Most importantly the whole family agreed. The leftovers were gone the next day. The gravy was awesome too & especially good mixed in with the leftovers to reheat in the microwave. Yum yum!! Thanks again for another restaurant worthy dinner 😋
Hi, could this recipe/method be used for a small leg fillet. Thanks in advance 🙂
Wow, great recipe! Made slight tweaks.
Created my go-to rub for lamb: a whole head of garlic cloves (peeled), 2-3 sprigs of fresh rosemary, 2 tbsp of olive oil, 2 tbsp of kosher salt, and 0.5 tbsp of pepper. Chop everything in food processor and then massage it into the meat. I mean, really massage it in. Don’t be shy. Wrapped the meat in plastic wrap and let it rest in the fridge overnight.
Took the lamb out of the fridge about an hour before cooking. Seared it on high in dutch oven, and then followed the recipe above (except I roasted the lamb in the dutch oven and obviously didn’t add more seasoning/ salt). In addition to the onions and garlic, I also added into the pot a few carrots and celery.
It came out absolutely delicious. Perfectly seasoned, tender and mouthwatering.
For gravy, I scooped up the fat and rosemary sprigs, and then I pureed the tenderized vegetables. The gravy was thickened by the carrots and celery, so didn’t need to use flour. A great trick for those of you abstaining from flour/ wheat!
Served everything on a bed of rice, handful of Persian cucumbers and tomatoes, with a spoon of greek yogurt, and couple of leaves of mint. No leftovers!
Absolute melt-in-your-mouth perfection. Cannot rate this recipe high enough. A huge crowd pleaser for sure!
This is my new favourite lamb roast recipe! Succulent, full of flavour, will make again- soon hopefully!
Leftovers were delicious.
I made it with a butterflied leg and stopped cooking 30mins early, sensational flavour and texture.
Thank you
Not sure where to start. All of your recipes are easy & so yummy. You are my guru
You drew me the picture of how to prepare..
And the lamb was kick ass.
First time lamb cooking
My Jewish girl Friend and friends were amazed.
Everyone was big Eyed.
Now I get to cook her family dinner. I’m not Jewish. Her family has been so good to me. I love them. I guess I’m changing religion’s.
Sincerely
Willy T from Nashville Tennessee
This is my go to lamb recipie. So easy! So good!
Great flavour and some of the meat was tender but some less so. I also found that all the pan juices cooked away, leaving nothing but fat in the pan so I couldn’t make the gravy. The 12 hour slow cooked lamb shoulder is amazing, and this is very good, but o wouldn’t say it was fool proof. I also needed to pull fairly hard to get some of the meat off the bone. It was very tasty though 🙂
Hi, is it possible to do the 4.5 hr slow cooking the day before, refrigerate it and do the 40 minute browning before the meal?
Hi!Is it possible to do the slow cooking the night before , put it in the fridge and brown it before the meal? Thank you
Perfection! The meat fell off the bone and was packed with rich, savoury flavour. The gravy was next level. I couldn’t resist mopping up every last bit with a piece of bread, just like I did as a kid. Thank you, Nagi, for another incredible recipe!
Best ever honestly. LOVED IT
Simple recipe but very delicious results. I tried it and of course my gravy was lumpy but straining helped. The leg was super juicy, tasty and incredibly fell of the bone. Lifetime recipe for me!
I didn’t have a roasting pan, so I used my largest casserole dish, but it made a mess so make sure there is a good amount of space between the liquid and the top of the dish. Everything went well after scooping some of the liquid out, I just added it back when making the gravy (in a separate pan). My first time making leg of lamb. Great recipe!
Does this freeze well after being cooked. Asking for a disability home. Thanks
How long do you pull lamb out of fridge to rest first b4 cooking or are people putting straight from fridge to oven for this recipe? Making today hopefully someone can help me out I’m confused on what to do lol
Thanks Nagi! This was delicious. I made this for my son’s birthday dinner tonight and it was amazing. I’m not the best at cooking protein and I’m super happy with the result. nagi you’re the best! X
just wondering if anyone has ever tried cooking 2 legs of lamb in the same oven with this recipe? Did cooking time change etc? should they be in seperate dishes?
Yes i did this at Easter 2025, cooked 2 legs together to feed 18. just cooked time to the largest piece and it all turned out great
It would depend on size of lamb. Two smaller legs eg 1-1.5 kgs may ft in large tin. If from 2-2.5 kgs I’d use two pans but again depends on oven size this time & whether your oven has a warmer area as some seem to. Great recipe for cold days.
I did two in the same pan before, no difference to the recipe.
Hi Emily – did you increase the gravy ingredients or leave as is with 2 in the same pan?
Amazing recipe! Making it again for our Christmas dinner! Has anyone ever tried to double the amount of liquid? I found with mashed potatoes as a side there wasn’t enough gravy. Wondering if I should put double the amount of beef broth in so that we have more gravy?