This roast leg of lamb with garlic and rosemary is one of those meals that feels special the moment it goes into the oven. With potatoes, onions, garlic, white wine, and a simple honey and vinegar finish, it turns into a full roast dinner with rich pan juices and tender slices of lamb.
Why You'll Love This Roast Leg of Lamb
- The lamb cooks over potatoes and onions, so everything absorbs the flavorful pan juices.
- Garlic, rosemary, white wine, honey, and vinegar create a rich, balanced sauce.
- It looks impressive but requires very little hands-on work.
- Perfect for holidays, Sunday lunches, or special family meals.
I love this recipe because it gives you a proper roast without making things complicated. The lamb roasts first until juicy, then the potatoes and onions go underneath so they can soak up all the flavor in the pan. It is the kind of meal I would happily make for Easter, Christmas, or a relaxed Sunday lunch when I want something that looks impressive but still feels simple to prepare. Recipes like my baked pork steaks and one-pan roasted chicken thighs and potatoes follow a similar approach: simple seasoning, good ingredients, and letting the oven do most of the work.
Key Ingredients for Roast Leg of Lamb with Garlic and Rosemary
You'll find the exact measurements in the recipe card, but here's a closer look at a few of the ingredients and why I use them.
- Lamb, Wine, and Oil: I use a bone-in leg of lamb for this recipe because it stays juicy and develops deeper flavor while roasting. White wine, olive oil, and water create the base for the pan juices that keep the lamb moist.
- Vegetables and Aromatics: Potatoes, onions, garlic, and rosemary roast underneath the lamb and absorb the flavorful juices as the meat cooks.
- Honey and Vinegar: A simple mixture of honey and vinegar brushed over the lamb near the end gives the roast a glossy finish and balances the richness of the meat.
How to Make Roast Leg of Lamb
You can find the complete printable recipe with measurements below, but for now, here's a quick overview of how it goes:
1. Prep the Lamb and Season Well: Bring the lamb to room temperature for about 1 hour, then place it in a roasting pan. Pour over the white wine, drizzle with extra virgin olive oil, add the water to the pan, and season well with salt and black pepper.
2. Start the Roast Hot for a Juicy Center: Roast at 425°F / 220°C (390°F convection / 200°C fan) on the middle rack for 1 ½ hours, basting occasionally, and then transfer the lamb to a plate.
3. Roast the Vegetables Underneath: Add the sliced potatoes, onions, garlic, and rosemary to the roasting pan, place the lamb back on top, and roast for 25 minutes at 390°F / 200°C (355°F convection / 180°C fan).
4. Finish with a Honey Glaze and Rest: Brush the lamb with the honey vinegar mixture and roast another 25 minutes. Let it rest for 15-20 minutes before slicing and serving with the vegetables.
Roast Leg of Lamb Cooking Time
For this recipe, the lamb cooks for about 2 hours and 20 minutes total, plus resting time.
Cooking time can vary depending on the size of the lamb and your oven. Many cooks estimate roughly 25 minutes per 500 g for medium doneness, but the most reliable way to check lamb is with a meat thermometer.
Best Internal Temperature for Roast Lamb
Internal temperature helps ensure the lamb is cooked the way you like it.
Typical ranges are:
- Medium-rare: 130-135°F / 54-57°C
- Medium: 140-145°F / 60-63°C
- Well done: 150°F / 65°C and above
For food safety, the USDA recommends lamb roasts reach 145°F / 63°C and rest before serving.
Bone-In vs Boneless Leg of Lamb
This recipe works best with a bone-in leg of lamb. The bone helps keep the meat juicy during roasting and gives the dish a deeper flavor.
Boneless leg of lamb can also work, but it may cook a little faster and is often tied into a rolled shape for even roasting.
Why This Roast Lamb Method Works
This recipe builds flavor in stages. The lamb roasts first with wine, oil, and water in the pan so it stays juicy while developing its own rich juices. Then the potatoes, onions, garlic, and rosemary are added underneath so they cook directly in those juices.
The final honey and vinegar glaze adds shine and a subtle balance of sweetness and acidity, which brings everything together beautifully.
How to Carve Roast Leg of Lamb
After resting for 15-20 minutes, transfer the lamb to a cutting board.
Slice the meat against the grain into thin slices. If the bone gets in the way, simply carve around it and continue slicing until you have enough pieces for serving.
My Tips for Roast Leg of Lamb
Choose the Best Spot in the Oven: I like keeping the roasting pan on the middle rack; it gives the lamb an even heat all around so the top browns nicely without the bottom overcooking.
How to Store and Reheat Roast Lamb
Store leftover lamb in an airtight container in the refrigerator for up to 3-4 days.
To reheat, place the lamb in a baking dish with a little of the pan juices or broth, cover loosely, and warm in the oven until heated through. This helps keep the meat from drying out.
What to Serve with Roast Leg of Lamb
This roast leg of lamb already cooks with potatoes and onions in the same pan, so you have a built-in side that absorbs all the flavorful juices from the lamb. To round out the meal, I like adding something fresh or crisp to balance the richness of the roast.
A simple salad works beautifully, and warm bread is always welcome for soaking up the pan juices. For a slightly bigger spread, you can also include a light vegetable dish or a Mediterranean-style salad that keeps the meal feeling bright and balanced.
Try These Lamb Recipes Next!
Recipe
Roast Leg of Lamb with Garlic and Rosemary
Ingredients
- 3 kg bone-in leg of lamb
- 100 ml white wine
- 50 ml extra virgin olive oil
- 100 ml water
- 1½ teaspoon salt
- ½ teaspoon freshly ground black pepper
- 4 potatoes - sliced
- 2 onions - sliced
- 10 cloves garlic
- 4 rosemary sprigs
- 2 tablespoon honey
- 1 tablespoon vinegar
Instructions
- Take the lamb out of the fridge at least 1 hour before roasting.
- Preheat the oven to 425°F / 220°C (390°F convection / 200°C fan) and set the rack to the middle level.
- Place the lamb in a roasting pan, pour the white wine over the meat, drizzle the extra virgin olive oil evenly across the top, and add the water to the pan. Season the lamb with salt and black pepper.
- Roast the leg of lamb for 1 ½ hours, basting occasionally.
- Take the leg of lamb out of the oven and place it on a plate.
- Place the sliced potatoes, sliced onions, garlic, and rosemary in the roasting pan. Return the lamb to the roasting pan over the vegetables and roast for 25 minutes at 390°F / 200°C (355°F convection / 180°C fan).
- Combine the honey and vinegar in a small bowl, brush the mixture over the lamb, and roast for a further 25 minutes.
- Rest the lamb for 15-20 minutes before slicing and serving with the vegetables.
Notes
Nutrition
Nutritional information is based on third-party calculations and should be considered an estimate only. Actual nutritional content will vary based upon brands used, measuring methods, cooking method, portion sizes, and more.
Sandra says
I made this roast leg of lamb last night, and it was exactly what I hoped for. The meat turned out tender, the potatoes soaked up all the flavor, and the honey–vinegar finish added such a beautiful touch.