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Slow Cooker Boneless Leg Of Lamb – boneless leg of lamb roast, cooked in the slow cooker with just a few simple ingredients. Learn how to prepare, season and cook boneless leg of lamb in the crock pot. This recipe is perfect to make year-round.
I stopped overcomplicating lamb – this slow cooker version is the easiest way to get tender, flavorful meat with minimal effort. It cooks low and slow, stays juicy, and works year-round, not just for holidays.
Table of Contents
- Why This Recipe Works
- What does lamb meat taste like?
- Is Lamb Hard to Cook?
- Ingredient Notes
- Best Seasoning for Lamb
- How to Cook Boneless Leg of Lamb in Slow Cooker
- Cooking Time & Temperature
- Why Use Mint on Lamb?
- Slow Cooker Time & Temperature
- What Is the Best Cut of Lamb for Slow Cooking?
- Other Lamb Cuts and How to Cook Them
- Extra Note
- Do You Need to Sear Lamb First?
- Can You Cook Lamb From Frozen?
- Tips for Cooking Boneless Leg of Lamb
- What to serve this Slow Cooker Boneless Leg Of Lamb with?
- More lamb recipes:
- Slow Cooker Boneless Leg of Lamb Recipe
Why This Recipe Works
- Optional broil step adds a crispy, roasted finish
- Slow cooking makes lamb tender, juicy, and forgiving
- Simple seasoning lets the natural flavor stand out
- Minimal prep – just season, set, and cook
- Works for both everyday meals and special occasions
What does lamb meat taste like?
I come from a part of the world, where lamb meat is popular and cooked quite often, but I know that a lot of people don’t like lamb or just haven’t had it cooked right.
If the smell of this meat is your concern, keep in mind that the younger the animal (needs to be under 1 year old), the less smell there will be.
It is best if you can find grass-fed lamb.
Seasoning helps with the flavor as well. If you absolutely can’t handle the smell and taste of lamb like a few people I know, just don’t cook or try to eat the meat.
Lamb meat has meaty flavor, stronger than beef and very distinct, you can never mistake the flavor for some other meat.
It has a texture firmer than chicken and softer than beef and it is a fatty meat, packed with good fats, perfect for low-carb diet. A meat with soft texture, distinct flavor, that melts in your mouth.
Is Lamb Hard to Cook?
Lamb is not difficult to cook – it just needs the right method.
For most home cooks, slow cooking is the easiest and most reliable option. It softens the meat, reduces the intensity of the flavor, and gives you a tender, juicy result with very little effort.
Roasting, on the other hand, creates a stronger flavor and firmer texture, but requires more precision to avoid overcooking.
If you want a no-fail approach, slow cooking is the way to go.
If you are looking for more lamb recipes to try at home, check these Lamb Loin Chops or Grilled Lamb Kebabs Recipe.
Ingredient Notes
This recipe uses a boneless leg of lamb, which is ideal for slow cooking because it stays moist and slices easily.
The seasoning is simple and balanced – garlic, thyme, and optional mint enhance the lamb without overpowering it.
Adding onion and liquid (stock + water or wine) creates a light cooking base that keeps the meat juicy and can be turned into gravy.
No need to over-season – lamb has a naturally rich, distinct flavor.
Best Seasoning for Lamb
Lamb pairs best with fresh, clean flavors:
- Garlic
- Thyme
- Rosemary (use lightly)
- Mint (classic, especially in Balkan cooking)
- Lemon (zest or juice)
Mint is especially important – it adds freshness and balances the richness of the meat.
How to Cook Boneless Leg of Lamb in Slow Cooker
- Season the lamb evenly on the outside
- Place sliced onion at the bottom of the slow cooker
- Add the lamb and garlic on top
- Pour in the liquid around the meat
- Cook until tender and fully done
- Optional: broil briefly for a golden crust
The result: soft, sliceable meat or easily shreddable texture if cooked longer.
Cooking Time & Temperature
- High: ~4 hours
- Low: 5–6 hours
- Target internal temp: 145–160°F (63–71°C)
This cut is very forgiving – slightly higher temperature won’t ruin it and often improves tenderness.
Why Use Mint on Lamb?
Mint adds freshness and balance to lamb’s naturally rich, bold flavor.
It can be used directly in the seasoning or added as part of a sauce, like a yogurt dip or herb-based topping.
In Balkan cooking, djodjen (Bulgarian spearmint) is the traditional choice. It has a milder, slightly sweeter flavor than regular mint, but works in the same way – bringing freshness and helping balance the richness of the meat.
Slow Cooker Time & Temperature
For a 3-4 lb boneless leg of lamb:
- High: 4 hours
- Low: 5-6 hours
- Internal temperature: 145-160°F (63-71°C)
For frozen lamb, add ~2 extra hours on low.
Doneness (What Actually Matters Here)
Unlike chops or rack of lamb, slow-cooked leg of lamb is very forgiving.
- 145°F → sliceable
- 155-160°F → more tender, easier to shred
For this recipe, slightly higher temperature = better texture.
What Is the Best Cut of Lamb for Slow Cooking?
The best cuts for slow cooking are:
- Leg of lamb (boneless or bone-in) – tender, sliceable, and easy to prepare
- Lamb shoulder – more fat, richer flavor, ideal for fall-apart texture
Both cuts become soft, juicy, and flavorful when cooked low and slow.
Other Lamb Cuts and How to Cook Them
Not all lamb cuts are suited for the slow cooker. Here’s how to use each one:
- Rack of lamb / lamb chops
Best cooked quickly – sear and finish in the oven or cook entirely on the stovetop - Lamb loin chops
Tender, steak-like cuts – cook fast, similar to rack of lamb - Lamb shank
Perfect for slow cooking or pressure cooking – becomes very soft and rich - Neck or neck fillet
Budget-friendly cut – ideal for stews and long cooking - Lamb rump
Naturally tender – best cooked quickly, then finished in the oven
Extra Note
In many Balkan and Mediterranean traditions, whole lamb is slow-roasted for special occasions. While not practical for everyday cooking, it highlights how well lamb responds to low, slow heat.
Do You Need to Sear Lamb First?
Not necessary.
For this method:
Broil after cooking for better texture and less effort
Skip searing before cooking
Can You Cook Lamb From Frozen?
Yes – just increase cooking time:
Always check internal temperature before serving
Add 2 extra hours on low
Tips for Cooking Boneless Leg of Lamb
- Use the leftover cooking liquid to make a quick gravy for serving
- Choose good quality lamb, preferably young and grass-fed for a milder flavor
- Keep seasoning simple – salt, pepper, garlic, thyme, and optional mint are enough
- Cook low and slow for a tender, juicy texture
- Check doneness toward the end if needed, but don’t stress – this cut is very forgiving
What to serve this Slow Cooker Boneless Leg Of Lamb with?
More lamb recipes:
Slow Cooker Boneless Leg of Lamb
Equipment
- 1 slow cooker
Ingredients
- 3 –4 lb boneless leg of lamb
- 1 tbsp salt
- 1/2 tsp black pepper
- 4 garlic cloves, chopped
- 2 tsp thyme
- 1 tsp dried mint, optional, but recommended
- 3 tbsp olive oil
- 1 onion, sliced
- 1 cup beef or vegetable stock
- 1 cup water, or substitute with stock
- Optional: 1/2 cup water + 1/2 cup red wine
Video
Instructions
- Season the lamb evenly on the outside.
- In a small bowl, mix olive oil, salt, pepper, thyme, and mint. Rub the mixture over the meat.
- Place sliced onion at the bottom of the slow cooker. Add the lamb on top.
- Sprinkle the chopped garlic over the meat. Pour in the stock and water (or wine mixture) around it.
Cover and cook:
- 4 hours on high, or
- 5–6 hours on low
- Remove the lamb and let it rest briefly. Slice or shred, depending on your preference.
- Optional: place under the broiler at 400°F (200°C) for 2–3 minutes to create a lightly crisp exterior.
Notes
- No need to season inside – slow cooking allows flavor to penetrate naturally
- Broiling at the end adds texture without extra work
- Add vegetables (potatoes, carrots) during the last 1-2 hours if desired
- Cook longer for a softer, shreddable result
- Use leftover juices to make a simple gravy
- Strain the cooking liquid. In a pan, melt 2 tbsp butter, add 1/4 cup flour, and cook briefly.
- Slowly whisk in about 3 cups of the cooking liquid. Simmer until thickened. Season to taste.
- Refrigerate for up to 3 days.
- Freeze in an airtight container for up to 2 months.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
This turned out very tender and delicious!
I made this dish tonight for my family. I was told, “This is the best lamb I have ever had”. It was so mild and delicious that I know I’ll be making it again! I can’t lie however, I added to the recipe. 1/8th cup of red wine vinegar and 1Tsp granulated Onion. No mint or rosemary. Oh, and I didn’t char it. But again the best lamb I’ve ever had.
Hi Jack,
so glad to hear your family liked the recipe! Love the addition of wine, and yes of course you can skip the mint and rosemary, lamb had great flavor on its own 🙂
Can you cook it like a rump roast with onions,carrots and potatoes
Yes, you can
The boneless leg of lamb comes with a thick layer of fat on the outside. I cut through the hunk of meat enough to allow the rub to penetrate some of the meat, but wasn’t sure whether to place it with the fat up or down in the crock pot. Any suggestion?
Fat up
I bought 0.45 kg or 1 lb of boneless lamb leg to slow roast in my slow cooker as I’m only cooking for one person. How long do you suggest to cook 1lb boneless leg lamb in a slow cooker on a low setting please?
Hi, it will probably take 4 hours on low.
Thank you. It turned out well on low for 4 hours for 0.45 kg. How long would I cook 1.15 kg boneless lamb leg on low setting in my slow cooker?
I seared the meat first before slow cooking as my slow cooker has a browning function when I tried your recipe for the first time. The meal was delicious. I added some vegetables to the slow cooker too (parnsip, carrot, onion and potato). I cut the potato into thick round pieces as I was concerned if the potato pieces were too big they wouldn’t cook well in 4 hours on low setting.
Hi Talia,
8 hours on low should be enough for this lamb leg.
Thank you. I think I cooked it for 6 hours on low setting as the recipe said 6 hours on low for a slighter bigger cut of boneless leg of lamb. It turned out well and the meat was tender.
Made this last night and the meat just fell apart. Juicy, melt in your mouth & full of flavour.
Spell check your recipe please. If I come to the interwebs and see your recipe which looks amazing, but I see until instead of untie……I doubt you as a chef. Do better. Especially to those seeing guidance that don’t speak English and know what you meant.
Thanks!
Thanks for your recipe. It looks yum. The only issue is there are no volumes for anything. How much stock? How much olive oil?
Hi, this is a recipe and everything is listed in the recipe card.