This Mary Berry Slow Roasted Lamb Recipe is a wonderfully tender and flavourful dish that is perfect for a relaxed Sunday lunch or a special family gathering. The lamb cooks gently in the oven for several hours, becoming beautifully soft and infused with garlic, rosemary, and rich pan juices. The result is melt-in-the-mouth meat with a golden, slightly crisp exterior. Despite its impressive flavour, the recipe is simple to prepare and mostly hands-off, with a total cooking time of around 4 hours.
Ingredients
For the Lamb
- 2–2.5 kg leg of lamb
- 4 garlic cloves, sliced
- 2 tbsp olive oil
- 2 tsp sea salt
- 1 tsp freshly ground black pepper
- 2 tbsp fresh rosemary, finely chopped
- 1 tbsp fresh thyme leaves
For the Roasting Base
- 2 large onions, thickly sliced
- 2 carrots, chopped
- 2 celery sticks, chopped
- 250 ml lamb or beef stock
- 150 ml dry white wine (optional)
For the Gravy
- 1 tbsp plain flour
- 250 ml lamb stock
- Salt and pepper, to taste
How to Make Mary Berry Slow Roasted Lamb
- Prepare the oven: Preheat the oven to 220°C or 200°C fan. Place a shelf in the lower-middle of the oven so the lamb cooks evenly and develops a golden crust.
- Prepare the lamb: Pat the lamb dry with kitchen paper. Using a small knife, make several small slits across the surface and insert the sliced garlic into the cuts.
- Season the meat: Rub the lamb all over with olive oil. Sprinkle with salt, black pepper, chopped rosemary, and thyme, pressing the herbs gently onto the surface.
- Prepare the roasting base: Spread the sliced onions, carrots, and celery across the base of a large roasting tin. Place the seasoned lamb on top of the vegetables.
- Add the liquid: Pour the stock and white wine around the lamb. This creates steam during cooking and forms the base of a delicious gravy.
- Start roasting: Roast the lamb uncovered for 20 minutes at the higher temperature to develop colour and flavour.
- Slow roast: Reduce the oven temperature to 160°C or 140°C fan. Cover the lamb loosely with foil and roast for about 3 to 3½ hours, basting occasionally with the pan juices.
- Rest the lamb: Remove the lamb from the oven and transfer it to a carving board. Cover loosely with foil and allow it to rest for at least 20 minutes before carving.
- Make the gravy: Place the roasting tin over medium heat on the hob. Sprinkle the flour into the pan juices and stir well. Gradually add the stock, whisking until smooth and slightly thickened. Season to taste.
- Carve and serve: Slice the rested lamb and serve with the hot gravy and roasted vegetables.

Tips for the Best Slow Roasted Lamb
How do I keep the lamb tender?
Slow cooking at a low temperature is key. Covering the lamb with foil helps retain moisture and ensures the meat becomes soft and succulent.
Should I baste the lamb during cooking?
Yes, basting the lamb with the pan juices every hour helps keep the meat moist and builds flavour as it roasts.
What cut of lamb works best?
A whole leg of lamb is ideal for slow roasting because it becomes tender while maintaining structure for easy carving.
Why is resting the lamb important?
Resting allows the juices to redistribute throughout the meat, making each slice juicier and easier to carve.
Serving Suggestions
- Roasted potatoes or crispy roast potatoes
- Buttered seasonal vegetables
- Mint sauce or fresh mint jelly
- Yorkshire puddings
- Creamy mashed potatoes
Storage
Room Temperature
Slow roasted lamb can sit at room temperature for up to 2 hours after cooking. After this time it should be refrigerated.
Refrigerator
Store leftover lamb in an airtight container in the refrigerator for up to 3 days. Reheat gently with a little stock to keep the meat moist.
Freezing
Cooked lamb freezes well for up to 2 months. Slice the meat first and store it in freezer-safe containers with a little gravy to prevent it drying out.
Nutrition
- Calories: 420 kcal
- Carbohydrates: 4 g
- Protein: 38 g
- Fat: 28 g
- Saturated Fat: 11 g
- Sodium: 520 mg
Nutrition values are estimates and may vary depending on ingredients used.
FAQs
How long should I slow roast a leg of lamb?
A 2–2.5 kg leg of lamb typically cooks for about 3 to 3½ hours at a low temperature. Slow roasting ensures the meat becomes tender and easy to carve.
Can I cook the lamb the day before?
Yes, you can roast the lamb a day ahead. Slice and store it in the refrigerator with some gravy, then reheat gently in the oven before serving.
Do I need to cover the lamb while roasting?
Covering the lamb loosely with foil during the slow roasting stage helps trap moisture and prevents the meat from drying out.
What temperature should lamb be cooked to?
For tender slow roasted lamb, aim for an internal temperature of about 90°C for shreddable meat or around 60–65°C for slightly pink slices.
Mary Berry Slow Roasted Lamb Recipe
Course: Main CourseCuisine: BritishDifficulty: Easy4
servings30
minutes40
minutes300
kcal1
hour10
minutesTender Mary Berry slow roasted lamb infused with garlic, rosemary and herbs, cooked slowly until melt-in-the-mouth and served with rich homemade gravy.
Ingredients
2–2.5 kg leg of lamb
4 garlic cloves, sliced
2 tbsp olive oil
2 tsp sea salt
1 tsp black pepper
2 tbsp fresh rosemary, chopped
1 tbsp fresh thyme leaves
2 onions, sliced
2 carrots, chopped
2 celery sticks, chopped
250 ml lamb or beef stock
150 ml dry white wine (optional)
Directions
- Preheat oven to 220°C (200°C fan).
- Make small cuts in the lamb and insert sliced garlic.
- Rub with olive oil, salt, pepper, rosemary and thyme.
- Place onions, carrots and celery in a roasting tin and sit the lamb on top.
- Pour stock and wine around the lamb.
- Roast for 20 minutes to brown the outside.
- Reduce heat to 160°C and roast covered for 3–3½ hours.
- Rest the lamb for 20 minutes before carving.
- Use pan juices and stock to prepare gravy.
Notes
- Slow roasting produces the most tender lamb.
- Baste occasionally to keep the meat moist.
- Leftover lamb is excellent in sandwiches or shepherd’s pie.
