BY Nagi

Prep: 15 mins
Cook: 4 hrs 59 mins
Yield: up to 8 servings

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, but you’ll be rewarded with tender lamb leg that can be pulled off the bone, served with a wickedly delicious rosemary garlic infused gravy.

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, 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.

And if blushing pink perfectly roasted lamb is what you’re after, try my Classic Roast Leg of Lamb – and yes, you really need a meat thermometer.

If you’re after a much easier, less stressful way to roast lamb leg, cook it long and slow. You won’t need a knife to carve this. Just pull the meat off the bone with tongs.

Ahhh, lamb, how I love thee! Some people love learning how to do fancy cake decorations. I admire from afar – I highly doubt you’ll ever see a towering 3 tier cake on here.

But big hunks of meat slow roasted until the meat is so tender, you can pry it off with a fork, then drown it in a gorgeous gravy infused with garlic and rosemary flavours? THAT you will find here!

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.

This Slow Roast Leg of Lamb is the latest in my roast lamb series – and it may well be the final “classic” recipe for my collection! I’ve previously shared: a Classic Roast Lamb Leg with Gravy (the type that’s perfectly blushing pink inside), Slow Cooker Roast Lamb (fall apart goodness in the convenience of your slow cooker), Slow Roasted GREEK Leg of Lamb (garlicky lemony fall apart deliciousness) and Slow Roasted Lamb Shoulder (slow is the only way it should be done!).

Am I missing any more “must haves” in my Roast Lamb collection? If I am, let me know in the comments below! – Nagi x

What You’ll Need

  • 2.25 kg / 4.5 lb leg of lamb , bone in (or shoulder) (Note 1)
  • Salt and pepper
  • 1.5 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 / 750 ml beef broth , low sodium
  • 2 cups / 500 ml water


  • 4 tbsp / 50g flour (white)
  • 1 cup / 250 ml water
  • Salt and pepper , to taste

How to Make It

  1. Preheat oven to 170C/335F (standard) or 150C/300F (fan/convection).
  2. Place garlic, onion and rosemary in a metal roasting pan.
  3. Place lamb leg right side up in the pan. (Note 2)
  4. Sprinkle generously with salt and pepper and rub it in.
  5. Turn lamb over and place it so it mostly sits on the garlic and onion. Sprinkle with more salt and pepper, rub it in.
  6. 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).
  7. Place in the oven and roast for 4.5 hours. (See Notes for roasting time table)
  8. Remove from the oven, remove foil. Turn lamb over. Check it to ensure the meat is tender (pry a bit off with a fork). If not, return, covered, to oven.
  9. Return uncovered lamb to oven for a further 45 minutes or until well browned.
  10. Remove lamb, spoon over pan juices generously. Transfer to serving platter, cover loosely with foil while you make the gravy (stays warm for 1 – 1.5 hours).


  1. Use a large spoon to skim off some of the fat from the surface of the liquid.
  2. Place pan on the stove on medium high. When the liquid bubbles, add flour.
  3. Use a whisk to mix it in – this may take a few minutes as the liquid reduces.
  4. 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.
  5. Strain gravy into a bowl, pressing juices out of the onion etc.
  6. Pour gravy into jug.


  1. The meat is tender so you will only need tongs to tear the meat off. Serve with gravy.
Recipe Notes

1. LAMB CUT: This recipe can be made with a leg or shoulder of lamb. Shoulder has more fat running through it than leg, so you can actually roast it uncovered (here’s my Slow Roasted Lamb Shoulder recipe), but this recipe will also work with shoulder. This recipe is designed for lamb leg because it’s leaner, so it benefits greatly from slow roasting partially submerged in liquid so it doesn’t dry out. Cooking it this way also infuses it with flavour.

2. The upper side of the lamb leg has more meat so we want to roast that partially submerged in the liquid for most of the cooking time. The upper side of the lamb is rounder and usually has more fat. The underside has less fat and is more flat.

3. TRY THIS WITH my Truly Crunchy Roast Potatoes!

4. MORE ROAST LAMB: Ultra Tender Slow Cooker Roast LambSlow Roasted Lamb Shoulder, Classic Roast Lamb with Gravy (i.e. it’s blushing pink inside) and Slow Roasted GREEK Leg of Lamb (delish lemon garlic flavours!).

5. Roasting Times:

Slow Roasted Lamb Leg Roasting Times

6. 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.