Delia Smith Roast Lamb with Garlic and Rosemary Recipe

This Delia Smith inspired roast lamb with garlic and rosemary is the sort of Sunday dinner that feels special without being fussy. The lamb roasts up juicy and tender, with crisp, salty edges and pockets of fragrant garlic and rosemary running through every slice. It’s a confident, straightforward roast that suits beginners, as long as you use a thermometer or follow the timing closely. Total time is around 2 hours, including a proper rest so the meat stays beautifully succulent.

Ingredients

For the Lamb

• 2 kg bone-in leg of lamb (take out of the fridge 45 to 60 minutes before roasting)
• 1 large garlic bulb, cloves peeled (about 12 to 16 cloves)
• 3 to 4 rosemary sprigs (or 2 tbsp finely chopped rosemary leaves)
• 2 tbsp olive oil
• 2 tsp fine sea salt
• 1 tsp freshly ground black pepper

For the Roasting Tray and Gravy

• 2 onions, thickly sliced
• 250 ml hot lamb stock (or chicken stock), plus extra as needed
• 150 ml dry red wine or white wine (optional, for extra depth)
• 1 tbsp plain flour (optional, for thickening)
• 1 tsp redcurrant jelly or mint sauce (optional, to round out the gravy)

How to Make Delia Smith Roast Lamb with Garlic and Rosemary

• Prepare the oven: Preheat the oven to 220°C (200°C fan). Place a shelf in the middle of the oven so the lamb roasts evenly. Sit the sliced onions in a large roasting tin and add a small splash of stock to stop them catching.
• Prepare the lamb: Pat the lamb dry with kitchen paper. Using a small sharp knife, make deep slits all over the lamb, especially where it’s thickest.
• Season and “assemble” the flavour: Push a garlic clove and a few rosemary leaves into each slit. Rub the lamb all over with olive oil, then sprinkle evenly with salt and black pepper.
• Start roasting: Place the lamb on top of the onions. Roast for 20 minutes at 220°C (200°C fan) to get the outside nicely browned.
• Roast until done: Reduce the oven to 190°C (170°C fan). Pour 250 ml hot stock into the tray (carefully, so you do not wash off the seasoning). Continue roasting until it reaches your preferred internal temperature, measured in the thickest part away from the bone: 55–57°C for medium-rare, 60–63°C for medium, 70°C for well done. For a 2 kg leg, medium is usually around 1 hour 10 minutes to 1 hour 30 minutes after the initial 20 minutes, but always go by temperature if you can.
• Rest (cooling step): Lift the lamb onto a warm plate or board and cover loosely with foil. Rest for 20 to 30 minutes. This gives you juicier slices and makes carving much easier.
• Make the gravy: Spoon off most of the fat from the roasting tin, leaving the dark juices behind. Place the tin over low heat on the hob (or tip everything into a saucepan). Add the wine, if using, and scrape up the sticky bits. Add a splash more stock if needed, then simmer for 5 to 8 minutes. For a thicker gravy, whisk the flour with a little cold water to make a smooth slurry, then whisk it into the simmering gravy and cook for 1 to 2 minutes. Stir in redcurrant jelly or mint sauce if you like.
• Carve and serve (assembling step): Carve the lamb across the grain into slices. Pour over a little gravy, serve the rest on the side, and bring it to the table while it’s still piping hot.

Tips

How do I stop roast lamb from drying out?

Do not skip the rest, and avoid overcooking. A thermometer is the simplest fix, but even without one, keep an eye on the tray and add a splash of stock if it looks dry. Resting for 20 to 30 minutes keeps the juices in the meat instead of on the board.

How do I get stronger garlic and rosemary flavour?

Make more slits than you think you need and push the garlic deeper into the meat. Use rosemary leaves (not just whole sprigs) inside the slits so the flavour is right in the centre of the joint.

What if the outside browns too quickly?

Loosely tent the lamb with foil once it’s the colour you like, then continue roasting at the lower temperature until it’s done inside.

How do I make gravy that isn’t greasy?

Spoon off the surface fat after roasting, then simmer the remaining juices with stock. If you have time, tip the juices into a jug and let the fat rise for a minute before skimming. It makes a big difference.

Serving Suggestions

• Roast potatoes, honeyed carrots, and steamed greens
• Yorkshire puddings and a big jug of gravy
• Mint sauce or redcurrant jelly on the side
• Leftovers in warm flatbreads with yoghurt and cucumber

Storage

Room Temperature

Do not leave cooked lamb out for more than 2 hours (or 1 hour in very warm weather). Carve what you need, then refrigerate leftovers promptly.

Refrigerator

Store leftover lamb in an airtight container for up to 3 days. Keep gravy separate if you can, so the meat does not get soggy.

Freezing

Freeze carved lamb in freezer-safe bags or containers for up to 2 months. Defrost overnight in the fridge, then reheat gently with a splash of gravy or stock to keep it moist.

Nutrition

• Calories: 520 kcal
• Carbohydrates: 3 g
• Protein: 48 g
• Fat: 34 g
• Saturated Fat: 14 g
• Sodium: 680 mg

Disclaimer: Nutrition values are estimates and will vary depending on the exact cut of lamb, portion size, and gravy used.

FAQs

Delia Smith Roast Lamb with Garlic and Rosemary Recipe

0.0 from 0 votes

Course: Main CourseCuisine: BritishDifficulty: Medium

Servings

8

people

Prep time

20

minutes

Cooking time

1

hour 

30

minutes

Total time

120

minutes

Calories

520

kcal

1

hour 

50

minutes

Tender, juicy roast leg of lamb studded with garlic and rosemary, with a simple pan gravy. A classic British roast that’s straightforward to make and full of savoury flavour.

Ingredients

• 2 kg bone-in leg of lamb (allow it to come to room temperature for 45–60 minutes)

• 1 large garlic bulb, cloves peeled (about 12–16 cloves)

• 3–4 rosemary sprigs (or 2 tbsp finely chopped rosemary leaves)

• 2 tbsp olive oil

• 2 tsp fine sea salt

• 1 tsp freshly ground black pepper

• 2 onions, thickly sliced (for the roasting tray)

• 250 ml hot lamb or chicken stock (plus extra if needed)

• 150 ml dry white wine or red wine (optional, for gravy)

• 1 tbsp plain flour (optional, to thicken gravy)

• 1 tsp redcurrant jelly or mint sauce (optional, for gravy)

• Fresh rosemary sprigs, to serve (optional)

Directions

• Preheat the oven to 220°C (200°C fan). Sit the sliced onions in a large roasting tin and add a splash of stock.
• Make small slits all over the lamb. Push in garlic cloves and rosemary leaves. Rub with olive oil, salt and black pepper.
• Roast for 20 minutes at 220°C, then reduce to 190°C (170°C fan). Roast until it reaches your preferred internal temperature (about 60–63°C for medium).
• Rest the lamb, loosely covered with foil, for 20–30 minutes.
• Make gravy from the tray juices: skim excess fat, deglaze with wine (optional), add stock, simmer, and thicken with flour if desired.
• Carve and serve with gravy and your favourite roast sides.

Notes

• A thermometer is the easiest way to get roast lamb exactly how you like it.
• Resting is not optional. It keeps the lamb juicy and makes carving cleaner.
• If the tray looks dry at any point, add a splash more stock to prevent scorching.