Slow cooker lamb leg is the set-it-and-forget-it answer to a special Sunday dinner. A bone-in leg of lamb cooks low and slow with garlic, rosemary, and lemon until it’s so tender it practically pulls apart, while the juices turn into a rich, savory sauce. This method is forgiving, hands-off, and delivers consistently moist, flavorful meat that slices or shreds beautifully.
Ingredients
- 1 bone-in leg of lamb (about 5–6 lb / 2.3–2.7 kg), trimmed of excess fat
- 6 garlic cloves, peeled and sliced into thin slivers
- 2 tbsp (30 ml) olive oil
- 1 tbsp (15 g) kosher salt
- 2 tsp (4 g) freshly ground black pepper
- 1 tbsp (6 g) fresh rosemary, finely chopped (or 1 tsp dried)
- 1 tbsp (6 g) fresh thyme leaves (or 1 tsp dried)
- 1 cup (240 ml) low-sodium beef or chicken broth
- 1 cup (240 ml) dry red wine (like Merlot or Cabernet) – optional, replace with extra broth if you prefer no alcohol
- 2 tbsp (30 ml) balsamic vinegar
- 1 large onion, sliced into thick rings
- 3 carrots, peeled and cut into 2-inch (5 cm) chunks
- 3 celery stalks, cut into 2-inch (5 cm) chunks
- 2 bay leaves
- 1 lemon, zested and juiced
- 2 tbsp (16 g) cornstarch mixed with 2 tbsp (30 ml) cold water (for gravy, optional)
Instructions
- Pat the lamb leg dry with paper towels. Using a small sharp knife, make 10–12 small slits (about 1 inch / 2.5 cm deep) all over the meat. Insert a garlic sliver into each slit.
- In a small bowl, mix the olive oil, salt, pepper, rosemary, and thyme. Rub this mixture all over the lamb, pressing it into the surface. Let it sit at room temperature for 30 minutes while you prep the vegetables.
- Heat a large skillet over medium-high heat. Sear the lamb on all sides until deeply browned, about 3–4 minutes per side. This step adds flavor but can be skipped if you’re short on time.
- Place the onion, carrots, celery, and bay leaves in the bottom of a 6–7 quart (5.7–6.6 L) slow cooker. Set the seared lamb on top of the vegetables.
- In a small bowl, combine the broth, red wine (if using), balsamic vinegar, lemon zest, and lemon juice. Pour this mixture around the lamb (not directly over the top, to keep the rub in place).
- Cover and cook on LOW for 8 hours, or on HIGH for 5–6 hours, until the lamb is fork-tender and reaches an internal temperature of 145°F (63°C) for medium-rare, or 160°F (71°C) for well-done, as measured with a food thermometer inserted into the thickest part without touching bone. The safe minimum for whole cuts of lamb is 145°F (63°C) with a 3-minute rest, but many prefer it more done.
- Carefully transfer the lamb to a cutting board, tent loosely with foil, and let rest for 20–30 minutes. This allows the juices to redistribute.
- Strain the cooking liquid through a fine-mesh sieve into a saucepan, discarding the vegetables and bay leaves (or keep them as a side). Skim off excess fat.
- To make gravy, bring the liquid to a simmer over medium heat. Whisk in the cornstarch slurry and cook for 2–3 minutes until thickened. Season with salt and pepper to taste.
- Slice the lamb against the grain, or shred it if it’s very tender. Serve with the gravy.
Tips
- Don’t skip the sear: Browning the lamb before slow cooking adds a deep, caramelized flavor that you can’t get from the slow cooker alone. If you’re truly pressed for time, you can skip it, but the dish will be less complex.
- Trim the fat: A leg of lamb can be fatty. Trim large chunks of external fat before cooking, but leave a thin layer to keep the meat moist. You can also ask your butcher to “fell” (remove the papery membrane) for you.
- Check the temperature: Slow cookers vary, so rely on a thermometer rather than the clock. The meat should be at least 145°F (63°C) for safety, but for fall-apart texture, you’ll likely cook it longer, reaching 180–190°F (82–88°C) — that’s fine and still safe.
- Make ahead: You can cook the lamb a day ahead, cool it in the liquid, then refrigerate. The next day, skim the solidified fat, reheat gently, and the flavor will be even better.
Serving Suggestions
Serve the sliced lamb over creamy mashed potatoes, polenta, or buttered egg noodles to soak up the gravy. A side of roasted green beans or a crisp arugula salad with lemon vinaigrette balances the richness. For a classic pairing, add a spoonful of mint jelly or a sprinkle of fresh chopped mint on top.
Variations
- Herb crust: Instead of just rubbing, press a mixture of chopped rosemary, thyme, garlic, and Dijon mustard onto the lamb before searing for a punchier flavor.
- Moroccan-inspired: Swap the red wine for orange juice, add 1 tsp ground cumin, 1 tsp ground coriander, 1/2 tsp cinnamon, and a handful of dried apricots in the last hour of cooking.
- Greek-style: Use lemon juice and oregano instead of red wine and rosemary, and add a cup of pitted Kalamata olives during the last 30 minutes.
- No wine: Replace the red wine with an equal amount of beef broth and add 1 tbsp (15 ml) extra balsamic vinegar for acidity.
Storage and Reheating
Refrigerate leftover lamb and gravy separately in airtight containers within 2 hours of cooking. The lamb will keep for 3–4 days in the fridge. To freeze, wrap the meat tightly in plastic wrap and then foil, or vacuum-seal; it will keep for up to 3 months. Thaw overnight in the refrigerator before reheating.
To reheat, place slices in a baking dish with a little gravy or broth, cover with foil, and warm in a 325°F (163°C) oven for 15–20 minutes, or until heated through to 165°F (74°C) for leftovers. You can also microwave individual portions in 30-second bursts, but the oven yields better texture. The gravy can be reheated in a saucepan over medium heat, stirring occasionally.
Frequently Asked Questions
Can I use a boneless leg of lamb? Yes, boneless works great. It will cook a bit faster (about 6–7 hours on LOW) and is easier to slice. Tie it with kitchen twine to keep its shape, and reduce the salt slightly since there’s less bone to absorb it.
Why is my lamb dry? Overcooking is the usual culprit, especially on HIGH. Slow cookers trap steam, but if you cook too long, the meat can dry out. Also, make sure there’s enough liquid — the broth and wine should come about a third of the way up the meat. Check at the lower end of the time range.
Can I cook this on HIGH? Yes, 5–6 hours on HIGH works, but the meat won’t be quite as fall-apart tender as 8 hours on LOW. The lower heat breaks down collagen more gently, so LOW is preferred for best texture.
How do I thicken the gravy without cornstarch? You can use a roux: melt 2 tbsp (28 g) butter, whisk in 2 tbsp (16 g) all-purpose flour, cook for 1 minute, then whisk in the strained liquid. Or, simply simmer the liquid uncovered for 10–15 minutes to reduce it naturally.
Is it safe to leave the slow cooker on while I’m at work? Yes, that’s the beauty of slow cooking. As long as the cooker is in good condition and on a stable surface, it’s safe to run unattended. Just make sure the lamb is fully thawed before cooking, and don’t lift the lid during cooking — you lose heat and add time.
Can I add potatoes to the slow cooker? Yes, add baby potatoes or quartered Yukon Golds to the bottom with the other vegetables. They’ll soak up the juices and be delicious. Keep them in large chunks so they don’t turn to mush during the long cook.
Related
- Simmering Vinegar to Remove Odors: How-To
- Simmering Steak Recipe: Tender, No-Fail Method
- Simmering vs Boiling: Key Differences & When to Use Each
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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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