There are few dinners more satisfying than a roast leg of lamb with golden potatoes and sweet roasted vegetables. It’s one of those meals that instantly makes the house smell AMAZING and feels just a little bit special, whether you’re cooking for Sunday lunch, Easter or a relaxed weekend dinner with family.
The brilliant thing about this roast leg of lamb recipe is how simple it is. Everything cooks together in one pan – the lamb, potatoes, carrots and onions -which means comfort food with minimal effort and very little washing up. Always a win!
The lamb is flavoured with garlic and fresh rosemary, two ingredients that are absolutely PERFECT with roast lamb. As the meat cooks, the juices run down into the vegetables underneath, making them incredibly flavourful and delicious.
Even better, this recipe doesn’t require complicated preparation or fancy techniques. A quick rub with olive oil, a few strategic cuts for the garlic and rosemary, and into the oven it goes. The result is a beautifully roasted lamb joint with tender vegetables and rich roasting juices.
If you’re looking for a simple roast lamb dinner that feels like proper comfort food without being complicated, this one pan roast leg of lamb is exactly what you need!
If you prefer a slower cooking approach, you might also enjoy my 5 hour slow cooked leg of lamb, which becomes beautifully tender and fall-apart soft.
Why You’ll Love This Roast Lamb Recipe
This recipe ticks so many boxes.
- First of all, it’s a true one pan meal. The lamb roasts on top while the vegetables cook underneath, soaking up all those wonderful juices.
- Second, it’s incredibly low effort. Once everything is in the oven, there’s very little to do apart from occasionally admire the incredible smell filling your kitchen.
- And finally, it’s a reliable crowd pleaser. Roast lamb has a rich, distinctive flavour that pairs beautifully with potatoes, carrots and rosemary. It’s the kind of dinner that people instinctively love.
This recipe is perfect for:
• Sunday lunch
• Easter dinner
• relaxed family meals
• feeding a crowd
• occasions when you want something impressive but EASY
In short: BIG flavours, minimal effort!
Ingredients
For this easy roast leg of lamb you’ll need:
- 1.5–2kg leg of lamb – A bone-in leg of lamb works beautifully for roasting and develops incredible flavour.
- Olive oil – Used to help the lamb crisp and the vegetables roast beautifully.
- Potatoes – White potatoes work particularly well because they become soft inside and golden on the outside.
- Carrots – These add sweetness and roast beautifully alongside the lamb.
- Onions – Roasting onions underneath the lamb adds incredible flavour to the vegetables and juices.
- Garlic – Garlic and lamb are a match made in heaven. Some cloves go into the lamb itself while the rest roast with the vegetables.
- Fresh rosemary – The CLASSIC herb for lamb. It adds wonderful aroma and flavour.
- Stock – Chicken or vegetable stock adds moisture and helps create delicious roasting juices.
How to Make Roast Leg of Lamb with Vegetables
This recipe is wonderfully straightforward. Once everything is prepared, the oven does most of the work!
1. Prepare the vegetables
Cut the potatoes and carrots into chunks roughly 2 inches in size so they cook evenly. Peel the onions and cut them into large chunks.
Spread the vegetables across the base of a deep roasting tin. Drizzle with 1 tablespoon of olive oil and sprinkle lightly with salt.
2. Prepare the lamb
Place the leg of lamb on top of the vegetables. Pierce the lamb around 20–30 times across the surface and rub the lamb with the remaining olive oil and sprinkle with salt. Add the sliced garlic and rosemary, then scatter the remaining garlic cloves and rosemary over the vegetables.
Pour the stock over the vegetables in the roasting tin. If you’re using a stock cube, simply pour the water into the tray and crumble the cube over the vegetables.
3. Cook the lamb
Cook in the oven at 180 degrees celsius for 35 minutes per 500g.
When it’s cooked, rest for at least 30 minutes for juicy, tender lamb.
Serve with the vegetables and juices from the pan spooned over the top.
Leg of Lamb Cooking Time Guide
One of the most common questions when roasting lamb is how long it should cook for. A good rule for this recipe is: 35 minutes per 500g at 180°C
Here’s a quick guide:
| Lamb weight | Cooking time |
| 1.5kg | ~1 hour 45 minutes |
| 1.8kg | ~2 hours |
| 2kg | ~2 hours 20 minutes |
Always allow the lamb to rest for at least 30 minutes after cooking.
This makes a HUGE difference to the tenderness of the meat.
How to Tell When Roast Lamb Is Cooked
Lamb can be served at a range of doneness levels, so it really depends on how you like it. For this recipe, cooking the lamb for around 35 minutes per 500g produces a beautifully cooked joint that is tender and juicy, with just a hint of pink in the middle.
If you want to be absolutely certain, a meat thermometer is the easiest way to check. Insert it into the thickest part of the lamb (avoiding the bone).
As a general guide:
• Medium rare: 55–60°C
• Medium: 60–65°C
• Well done: 70°C+
Remember that the temperature will continue to rise slightly while the lamb rests, which is another reason the 30 minute resting time is so important.
If you don’t have a thermometer, you can also check by piercing the lamb with a knife. The juices should run clear with a slight pink tint, not deep red.
Should You Cover Lamb When Roasting?
For this recipe, the lamb is roasted uncovered, which helps the outside develop a beautiful golden crust while the inside stays tender.
Because the vegetables and stock sit underneath the lamb, they help create moisture in the roasting tray and prevent the meat from drying out. This means you don’t need to cover it with foil while cooking.
However, once the lamb has finished roasting and comes out of the oven to rest, it’s a good idea to loosely cover it with foil. This keeps it warm while the juices settle back into the meat.
The result is lamb that’s tender, juicy and full of flavour – exactly what you want from a great roast dinner!
Tips for Roasting the Best Leg of Lamb
Roasting a leg of lamb is wonderfully simple, but a few small tricks make a big difference.
- Use fresh rosemary – Rosemary and lamb are a CLASSIC combination. Fresh rosemary gives the best flavour and aroma as the lamb cooks.
- Let the lamb come to room temperature – If possible, take the lamb out of the fridge about 30 minutes before cooking. This helps it cook more evenly.
- Cut the vegetables large – Large chunks of potato, carrot and onion roast much better than small pieces. They stay tender inside while developing golden edges.
- Rest the lamb properly – Resting the lamb for at least 30 minutes makes the meat much more tender and juicy.
What to Do with the Roasting Juices
One of the BEST parts of this recipe is the incredible roasting juices left in the pan.
As the lamb cooks, the juices mix with the garlic, rosemary and vegetables to create an intensely flavourful base.
You can simply spoon these juices over the lamb and vegetables when serving, or turn them into a quick gravy.
To make a simple gravy:
- Remove the lamb and vegetables from the roasting tray.
- Place the tray over a medium heat on the hob.
- Stir in a teaspoon of flour and cook for a minute.
- Add a splash of stock or water and whisk until smooth.
The result is a rich, savoury gravy that’s absolutely perfect with roast lamb.
Roast Leg of Lamb with Vegetables (Easy One Pan Lamb Roast Recipe)
Ingredients
- 1.5-2 kg leg of lamb
- 2 tbsp olive oil
- 6-8 white potatoes
- 5 large carrots
- 2 onions
- 1 bulb garlic
- 10 g fresh rosemary
- 350 ml vegetable or chicken stock
- 1.5 tsp salt
Instructions
- Preheat the oven to 180°C (350°F).
- Cut the potatoes and carrots into chunks about 2 inches in size so they cook evenly. No need to peel.
- Peel the onions and cut them into large chunks.
- Spread the potatoes, carrots and onions across the base of a deep roasting tin. Drizzle with 1 tablespoon of olive oil and sprinkle lightly with salt.
- Place the leg of lamb on top of the vegetables, skin side up.
- Using a sharp knife, pierce the lamb 20–30 times across the surface.
- Rub the lamb with the remaining 1 tablespoon olive oil and sprinkle with about 1 teaspoon salt.
- Slice 4 cloves of garlic and insert a slice of garlic and a small sprig of rosemary into each of the holes in the lamb.
- Scatter the remaining garlic cloves and rosemary over the vegetables. There is no need to peel the extra garlic cloves.
- Pour the stock over the vegetables in the roasting tin. If using a stock cube, pour over the water and crumble the cube directly over the vegetables.
- Roast the lamb in the oven for 35 minutes per 500g.
- Remove from the oven and allow the lamb to rest for 30 minutes before carving.
- Serve the lamb with the roasted vegetables and spoon over the delicious roasting juices.
Notes
Storing and Using Leftover Roast Lamb
One of the best things about cooking a leg of lamb is the leftovers. Leftover roast lamb can be used in all sorts of delicious meals. Some favourites include: • lamb sandwiches• lamb fried rice
• shepherd’s pie
• lamb pasta dishes
• lamb salads If stored in the fridge, leftover lamb will keep well for 5 days. You can also freeze cooked lamb for up to 3 months.
Love Cooking Lamb? Try These Recipes Too
If you enjoy this roast lamb recipe, you might also like some of my other lamb dishes.
For a completely different approach, take a look at my 5 Hour Slow Cooked Leg of Lamb. Instead of roasting quickly, this version cooks low and slow until the lamb becomes incredibly tender and falls apart beautifully.
And if you happen to have leftovers from your roast, don’t let them go to waste! My Leftover Roast Lamb Shepherd’s Pie is a fantastic way to turn leftover lamb into a rich and comforting dinner.
Or if you fancy something a bit different, try my Leftover Roast Lamb Biryani – another brilliant way to transform roast lamb into a completely new meal.
More Easy Dinner Recipes
If you’re looking for more comforting meals like this one, you might enjoy exploring some of my recipe collections.
Take a look at:
• Easy Weeknight Dinner Recipes – a huge collection of reliable dinners
• Comfort Food Recipes – satisfying meals for chilly evenings
• One Pot and One Pan Recipes – minimal washing up, maximum flavour
• Leftover Recipes – clever ways to turn yesterday’s roast into something new
Cooking delicious dinners doesn’t need to be complicated – sometimes the simplest recipes are the BEST!