Roast Leg of Lamb with Rosemary and Garlic
This Roast Leg of Lamb with Rosemary and Garlic recipe is made for a Christmas table where everyone helps themselves. Garlic tucked into the meat, chopped rosemary and a little lemon zest give the lamb plenty of flavour without a long marinade or a complicated shopping list.
For a hot South African Christmas, serve it with a crisp green salad, chilled potato salad and sliced tomatoes rather than a full spread of hot sides. The lamb rests while you finish the salads, leaving the last few minutes pleasantly unhurried.
A bone-in leg makes a generous centrepiece, and the onions underneath catch the roasting juices. Use a meat thermometer to judge doneness: the shape of the leg matters as much as its weight.
Ingredients
For the lamb
For the gravy
Instructions
- 1Heat the oven to 200°C, or 180°C fan. Take the lamb out of the fridge while you prepare the ingredients, keeping this time to about 20–30 minutes, especially in a hot kitchen. Pat it dry with kitchen paper.
- 2Using a small, sharp knife, make shallow slits all over the meaty parts of the leg. Push a garlic sliver into each slit. Mix the rosemary, olive oil, lemon zest, lemon juice, salt and pepper, then rub over the lamb.
- 3Spread the onion wedges in a sturdy roasting tin just large enough to hold the lamb. Place the lamb on top, fat-side up, and pour the first 250 ml stock around it, not over the seasoned surface.
- 4Roast for 20 minutes. Reduce the oven to 180°C, or 160°C fan, and roast for a further 70–90 minutes as a guide. Check the liquid occasionally and add a splash of hot water if the tin is drying out. Loosely cover the lamb with foil if it browns too quickly.
- 5Begin checking the temperature after about 75 minutes of total roasting time. Insert a meat thermometer into the thickest part without touching bone. For this recipe, roast until it reaches at least 63°C; this usually takes about 90–110 minutes in total, but allow longer if needed. For less pink meat, cook to 70–75°C.
- 6Transfer the lamb to a warm platter, cover loosely with foil and rest for 20–25 minutes before carving. Keep the onions to serve alongside, and save any juices that collect on the platter.
- 7For the gravy, spoon off most of the fat from the roasting tin, leaving about 15 ml with the browned juices. If the tin is hob-safe, place it over medium heat; otherwise scrape the juices into a saucepan. Stir in the flour and cook, stirring, for 1 minute.
- 8Gradually whisk in the remaining 250 ml stock, scraping up the browned bits. Simmer for 5–8 minutes until lightly thickened, then stir in the resting juices. Add a little more stock if needed and taste before adding any extra seasoning.
- 9Carve the lamb across the grain, working around the bone. Serve with the roasted onions and hot gravy, with cool salads on the side.
Nutrition (per serving)
- Calories
- 430 kcal
- Carbohydrates
- 6 g
- Protein
- 43 g
- Fat
- 26 g
- Saturated fat
- 10 g
- Sugar
- 2 g
- Fibre
- 1 g
- Sodium
- 650 mg
- Cholesterol
- 140 mg
Estimated values based on the ingredients used.
Notes
Christmas tips
- Prepare the garlic and rosemary rub a day ahead, rub it onto the lamb and refrigerate in a covered container. Keep raw meat on the lowest fridge shelf, away from ready-to-eat food.
- Plan for roughly 110 minutes in the oven plus 20–25 minutes of resting. Start a little earlier if your Christmas oven is crowded, and use the thermometer rather than the clock as your final guide.
- On a hot day, let chilled salads do most of the supporting work. Keep them refrigerated until serving, and put the gravy in a jug so guests can choose how much they want.
- Refrigerate leftover lamb in shallow containers within 2 hours of cooking, or within 1 hour if the temperature is above 32°C. Eat within 3–4 days or freeze for another meal.
Frequently asked questions
Can I use a boneless leg of lamb?
Yes. Use a boneless leg tied securely into an even shape. Its cooking time will differ according to weight and thickness. Follow the supplier's cooking guidance, especially for rolled or stuffed joints, rather than relying on the bone-in timing here.
How do I avoid dry roast lamb?
Use a meat thermometer and avoid cooking past your preferred doneness. A whole, unstuffed leg should reach at least 63°C and rest for at least 3 minutes for food safety; the longer 20–25 minute rest in this recipe also makes carving easier. Do not slice it as soon as it leaves the oven.
Can I roast potatoes with the lamb?
Yes, but use a separate tray so they roast rather than sit in the stock. Parboil potato chunks, drain well, roughen the edges and toss with oil and salt. Roast alongside the lamb until tender, then increase the oven to 220°C while the meat rests to finish crisping them, checking regularly.
