Tender Roast Leg of Lamb coated with a simple but flavourful herb and lemon rub and served with rich, meaty gravy.
I think a good quality joint of lamb has got to be one of the most flavourful meats going.
The natural fat in a lamb joint ensures the meat is juicy and succulent, and it's actually a particular fatty acid in lamb fat that gives it its distinctive rich and slightly gamey flavour.
According to Cook’s Illustrated “Meat Book” cookbook (note: this is an affiliate link. Also it's one of my favourite books to understand everything you need to know about meat), grass-fed lamb is best - because a diet of this type (rather than grain-fed) results in a higher concentration of branched chain fatty-acids - which leads to a more flavourful and sweeter-tasting meat.
Grass-fed lamb from Wales is excellent, as it rains so much over there that the grass is perfectly green and lush (check out my shoulder of lamb post for more insight on Welsh lamb following a Welsh lamb trip that Chris and I attended last year).
Imported lamb from New Zealand or Australia is also generally grass fed.
Lamb from the USA is often grain-fed, or partially grain-fed. British lamb is sometimes supplemented with grain feed - usually when the grass is past its best. So be sure to look out for grass-fed lamb for the best flavour.
Here's what you'll need
Step to make Roast Lamb
Full ingredients and recipe in the recipe card below
- Mix together olive oil, garlic salt, salt, pepper, rosemary, thyme and lemon zest and spread all over the lamb.
- Place the lamb in a large roasting tin and roast in the oven. Cook for 2 hours
- Take the lamb out of the oven and allow to rest while you make the gravy.
Making the lamb gravy
- Heat the meat juices (be sure to scrape up any bits from the tin – that’s where all the flavour is) in the roasting tin or in a pan over the hob together with crumbled stock cubes and hot vegetable water (from cooking your veggies).
- Bring to the boil and lightly season with salt and pepper, then stir in a cornstarch slurry using a whisk, until the gravy thickens.
Serve the roast lamb with the gravy alongside veggies and plenty of mint sauce.
You can use shop-bought mint sauce, or check out how to make my easy homemade mint sauce:
What shall I serve with Roast Lamb and Gravy?
- Easy Mint Sauce(I know I've said it once or twice, but that's how much I love the stuff)
- Potatoes!! You could go for my crispy-yet-fluffy Roast Potatoes or these decadently creamy Dauphinoise Potatoes, or creamy, fluffy Mashed Potatoes
- Simple butter pepper Carrots
- Cheats cauliflower cheese
- Green Beans with Garlic and Parmesan
Pro Tips for the Juiciest Roast Lamb
- Check your oven temperature! Oven temperature is often inaccurate, especially in older ovens. Use an oven thermometer to check the internal temp of your oven is correct.
- Make sure the lamb isn't too lean. Fat = flavour. It also equals juiciness. Try to pick a lamb leg with plenty of visible fat on the outside and nice light marbling of fat inside.
- Leave to rest for a minimum of 20 minutes (ideally 30 minutes). This allows the juices, which are driven to the center of the meat during cooking, to redistribute themselves throughout the meat, resulting in juicier slices of meat (yep I'm quoting that Cook’s Illustrated “Meat Book” cookbook again <--affiliate link).
Should I cover the lamb when roasting?
There's no need to cover a leg of lamb during roasting (I would use foil with a shoulder of lamb however, as it's in the oven longer).
Check out my Roast Dinner category for lots of roast dinner ideas.
Watch how to make it
Roast Leg of Lamb with Rich Gravy
- 2 kg leg of lamb
- 1 tbsp olive oil
- ½ tsp garlic salt
- ½ tsp Maldon salt
- ½ tsp black pepper
- 1 tsp dried rosemary
- 1 tsp dried thyme
- Finely grated zest of 1 lemon
For the gravy:
- Meat juices from your roasted lamb
- 2 lamb stock cubes crumbled
- 1 beef stock cube crumbled
- 3 cups 720ml hot vegetable stock - from your boiled/steamed vegetables and potatoes
- 1/4 tsp salt
- 1/4 tsp black pepper
- 2 tbsp cornflour/cornstarch
- 5 tbsp cold water
- Remove the lamb from the fridge about an hour before cooking – to allow it to come up to room temperature.
- Preheat the oven to 180C/350F
- Mix together the olive oil, garlic salt, salt, pepper, rosemary, thyme and lemon zest to form a thick paste.
- Spread the paste all over the lamb.
- Place the lamb in a large roasting tin and place in the oven. Cook for 2 hours (this will cook it to medium).
- Remove from the oven and place on a warm plate to rest for 30 minutes.
- To make the gravy, place the roasting tin on the hob (or transfer the meat juices to a saucepan – be sure to scrape up any bits from the tin – that’s where all the flavour is).
- Sprinkle on the crumbled stock cubes.
- Stir together whilst pouring in the hot vegetable water. Bring to the boil and lightly season with salt and pepper.
- Stir in a the cornstarch slurry using a whisk, until the gravy thickens. Allow to bubble then turn off the heat.
The Lamb:Go for grass-fed lamb for the absolute best flavour. You're looking for a lamb leg with a layer of fat on the outside, and lightly marbled with fat on the inside. Welsh lamb is my favourite, but New Zealand lamb is great too.
Different lamb leg size?Here are the recommended cooking times for full leg and half leg joints: Medium: Cook for 25 minutes per 500g (1.1lbs), plus an extra 20-25 minutes at 180C/350F - until the internal temperature of the lamb is 60C. Well done: Cook for 30 minutes per 500g (1.1lbs), plus an extra 25-30 minutes at 180C/350F - until the internal temperature of the lamb is 70C.
Nutritional information is per serving including gravy.
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