Description
This easy roast leg of lamb recipe features succulent lamb infused with rosemary, garlic, and optional anchovies, roasted to perfection on a bed of onions. The simple seasoning and roasting technique deliver a tender, flavorful centerpiece perfect for family dinners or special occasions.
Ingredients
Scale
Meat and Seasonings
- 2kg-2.5kg leg of lamb
- Small bunch rosemary, cut into 2cm short sprigs
- 4–5 garlic cloves, finely sliced
- 4–6 brown anchovy fillets, chopped (optional)
- 2 tbsp olive oil
- Salt and freshly ground black pepper, to taste
Vegetables
- 2 large onions, thickly sliced
Instructions
- Prepare the lamb: Preheat your oven to 220C/200C fan/gas 7. Remove all packaging from the leg of lamb and note its exact weight to calculate cooking time accurately. Using a small, sharp knife, make angled incisions about 5cm deep into the meat to maximize flavor infusion.
- Insert flavorings: Into each incision, insert a short rosemary sprig, a slice of garlic, and a small piece of anchovy fillet if using. Press firmly to ensure the flavorings stay in place.
- Season and oil: Season the entire leg of lamb generously with salt and freshly ground black pepper. Rub all over with 2 tablespoons of olive oil to help the surface crisp up during roasting.
- Prepare for roasting: Spread the thickly sliced onions evenly in a roasting tin. Place the lamb on top of the onion bed to cook.
- Initial roasting: Roast at 220C/200C fan/gas 7 for 20 minutes to develop a nice crust.
- Adjust temperature and continue roasting: Reduce oven temperature to 190C/170C fan/gas 5. Roast the lamb for an additional 15-20 minutes per 500g, so around 1 hour to 1 hour 20 minutes for a 2kg leg, depending on how pink you prefer the lamb. For precise doneness, use a meat thermometer: 55C for medium rare (pink), up to 70C for well done.
- Rest the meat: Remove the lamb from the oven, cover loosely with foil, and let it rest for 15 minutes to allow juices to redistribute.
- Serve and use pan juices: Carve the lamb and serve. Use the cooked onions and tray juices as a flavorful base to make gravy.
Notes
- Making angled slits helps the flavor penetrate more deeply without pushing out during roasting.
- The anchovy fillets add a subtle umami depth but can be omitted for a milder flavor.
- Resting the meat is essential for juicy roast lamb.
- You can use a meat thermometer to take the guesswork out of cooking time and achieve your preferred doneness.
- The bed of onions imparts sweetness and moisture to the lamb and can be mashed or pureed for gravy.
- Prep Time: 15 minutes
- Cook Time: 1 hour 20 minutes
- Category: Main Course
- Method: Roasting
- Cuisine: British
Keywords: roast leg of lamb, lamb roast, rosemary lamb, garlic lamb, oven roast lamb, easy roast lamb
