Meet your new favourite roast dinner: Slow Cooker Leg of Lamb. This low-effort method yields tender, flavourful meat and a rich gravy with minimal fuss.
If you’ve bought a leg of lamb but aren’t sure how to cook it, this Slow Cooker Lamb Leg recipe is for you. It removes the guesswork and keeps Sunday lunch simple and relaxed.
This slow-cooked method is hands-off but produces succulent, flavour-packed meat and its own delicious gravy.
❗️Note: Make sure the joint will fit in your slow cooker before you buy it.
Why you’ll love this Slow Cooker Lamb Leg recipe
⭐️ Almost no prep — very convenient
⭐️ Foolproof, fuss-free roast dinner
⭐️ Deep, satisfying flavour
Quick Tip
If you want a crispy top and a glossy mint glaze, finish the cooked joint in a hot oven for 20–30 minutes. The lamb is perfectly tender straight from the slow cooker, but a brief blast in the oven adds colour and texture and lets a mint jelly form a lovely crust.
Slow Cooker Leg of Lamb Ingredients
- Lamb leg – Boneless, rolled lamb leg so it fits your slow cooker.
- Sea salt and freshly ground black pepper – Season generously.
- Garlic – Fresh or frozen, chopped or crushed.
- Vegetables – Onions and carrots, roughly chopped to flavour the cooking liquid.
- Lamb stock – Hot stock from a cube or homemade.
- Cornflour (corn starch in the US) – Make a slurry to thicken the gravy.
- Soy sauce – A splash to deepen the gravy flavour (light soy works well).
- Mint jelly – Optional for glazing if you finish the joint in the oven.
How to cook a leg of lamb in a slow cooker
1. Place the garlic, onions, carrots, lamb leg and hot stock into the slow cooker. Season with salt and pepper.
2. Cook on HIGH for about 10 hours or LOW for 12 hours. When the lamb is cooked, transfer it to a roasting tin, spread the mint jelly over the top and place under a hot grill or in a hot oven for 20–30 minutes to brown and glaze, if you like.
3. While the lamb is browning, skim off excess fat from the cooking liquid. Take a few tablespoons of the juices into a bowl and whisk in the cornflour until you have a smooth slurry.
4. Stir the slurry back into the slow cooker juices, add the soy sauce, and heat until the gravy thickens. You can leave it on HIGH in the slow cooker for about 30 minutes or simmer on the hob for 5–10 minutes if the slow cooker pan is stove-safe. Serve the lamb with the gravy and the cooked vegetables.
Leftovers
In the fridge: Store cooled leftovers in an airtight container for up to 3 days.
Leftover lamb reheats well with pasta or rice; it’s especially good with orzo which soaks up the gravy. You can also use the meat in stews, curries or sandwiches.
Freezing: Leftover lamb freezes well in its gravy. Defrost overnight before reheating. Freeze extra gravy flat in freezer bags for easy storage and later use.
FAQs
Start the slow cooker early in the morning or use the LOW setting and cook for longer. If needed, use a timer to switch the slow cooker on at a set time so the joint finishes when you want it to.
No. For this recipe it’s better to brown after slow cooking. Browning the meat once much of the fat has rendered gives you a crisp crust and tender interior.
Classic choices include roast or mashed potatoes, cauliflower cheese, seasonal vegetables, and Yorkshire puddings. The lamb’s gravy pairs nicely with starchy sides that soak it up.
Try the recipe and let us know how it turned out. If you share photos, tag the account you use on social media — we’d love to see your creations.
Slow Cooker Leg of Lamb {Easy Recipe}
Ingredients
- 2 kg Lamb leg (boneless, rolled)
- 3 Garlic cloves, peeled and crushed
- 2 Large onions, peeled and cut into chunks
- 3 Large carrots, peeled and chopped
- 400 ml Hot lamb stock
- 3 tbsp Cornflour
- 100 g Mint jelly
- 2 tbsp Soy sauce
- Sea salt and freshly ground black pepper
Instructions
- Put the garlic, onions, carrots, lamb leg and stock into the slow cooker. Add salt and pepper.
- Cook on HIGH for approximately 10 hours or LOW for 12 hours.
- When cooked, transfer the meat to a tin, spread with mint jelly and bake at 220°C fan / 240°C conventional / Gas Mark 9 for 20–30 minutes or until browned, if desired.
- Remove the carrots and onions and set aside.
Meanwhile, make the gravy:
- Skim off the fatty layer from the cooking liquid. Reserve the juices.
- Place a few tablespoons of the reserved liquid into a bowl and whisk in the cornflour until smooth to make a slurry.
- Stir the slurry back into the pan, add the soy sauce and heat until the gravy thickens. Keep warm and serve with the lamb and vegetables.
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Notes
Searing the lamb: Browning after slow cooking gives the best contrast: a crispy top and a tender interior.
Oven finish (optional): A brief bake with mint jelly creates an attractive, flavourful glaze.
Timing: The lamb is forgiving — you can cook on LOW for longer or use a timer to start the slow cooker so it’s ready when you need it.
Removing excess fat: Spoon off the fat layer before making the gravy or use a fat separator if you have one.