A leg of lamb is the traditional choice for your Easter lunch, but we shouldn’t be looking for an excuse for this beautifully tender piece of meat to take centre stage at any roast dinner. But knowing how to prepare, cook, and carve lamb can be tricky — especially if you’re new to cooking.
Chef Peter Sidwell talks us through his tips and tricks for creating show-stopping roast lamb. You’ll be cooking up crispy on the outside and deliciously juicy on the inside, leg of lamb in no time!
How to prepare a leg of lamb
How to marinate a leg of lamb
When it comes to roasting a leg of lamb, the first step is to marinate it. This works wonders at adding and enhancing deep flavours in your meat. Not only that: marinades with acidic ingredients like lemon break down tough proteins in the meat, giving you melt-in-the-mouth deliciousness.
But, as lamb is already naturally tender, you should only leave your marinade on for around four hours; overdoing it could cause it to have a mushy texture.
And remember, it's always best to check the packaging of your leg of lamb for the weight or use kitchen scales to measure it, as this will give you an idea of how long it needs to be cooked. Weighing before the marinade goes on will be much easier and less messy.
Peter tells us his favourite marinade for lamb: "Rosemary and garlic are a natural option for lamb, as they compliment it beautifully. However, cumin, lemon, and dried mint are also a fantastic combination of flavours."
To make a classic garlic, rosemary, and lemon marinate, you need to:
Pop your leg of lamb into a roasting tin.
Pick a few sprigs of fresh rosemary and roughly chop.
Add the garlic and chopped rosemary to a medium-sized mixing bowl.
Mix in the zest and juice of one lemon.
Pour in a good lug of olive oil (around 50ml) before mixing until combined.
Create piercings in the lamb by inserting a knife a third of the way in and repeating until covered, leaving around an inch between each incision.
Season your lamb by sprinkling over a little salt and pepper.
Spoon your marinade over your meat and rub it in (using your hands is best, but a piece of kitchen roll will also work).
Place your lamb in the fridge for two to three hours.
Bone in or out?
When prepping your lamb, you may wonder whether you should leave the bone in or remove it. There’s no right or wrong answer!
Peter explains, “roasting a leg of lamb with the bone in will help keep it moist and juicy. However, it will take longer to cook, so removing the bone may be the best option if you want to save money by cutting down on the time your oven is on.”
When you cook lamb with the bone in, the meat can absorb extra moisture from it. Although boneless lamb is often easier to cut, you may be left with a drier, tougher texture.
And cooking with the bone in will undoubtedly result in a tastier piece of meat, as it holds lots of flavours that are released when cooked.
If you do decide to debone, make sure to use a sharp knife and follow these steps:
Run a knife along the side of the leg until you feel the bone.
Use your fingers to open up the area where you can easily insert your knife.
Carefully cut along either side of the bone until you’ve removed it.
Once deboned, your lamb will need to be held together, ready for cooking. You can tie it together yourself using kitchen twine or ask your butcher to do this for you.
Or, to make things easier, you could buy a pre-prepared boneless leg of lamb.
How to cook a leg of lamb
How long you need to cook your leg of lamb depends on factors like the size, how cooked you like it, and whether you have the bone in or out.
Before cooking your piece of lamb, remember to weigh it and use the following times as a rough guide.
With the bone
- Medium — 25 minutes per 500g, plus 25 minutes
- Well done — 30 minutes per 500g, plus 30 minutes
- Medium — 30 minutes per 500g, plus 30 minutes
- Well done — 35 minutes per 500g, plus 35 minutes
However, it’s always best to use a thermometer to check your meat is done, as the shape and fat content in your lamb may change the speed it cooks.
Peter says, “lamb should be super tender and fall off the bone effortlessly.” Medium-rare lamb that’s slightly pink and juicy in the middle will give these results, but it’s all down to personal preference. The following temperatures when you probe your thermometer into your lamb will give you an idea of how cooked it is:
- Rare — 48-54°C
- Medium-rare — 55-59°C
- Medium — 60-66°C
- Well-done — 67-74°C
What temperature to cook a leg of lamb
It’s best to start cooking your lamb at 220°C/200°C fan/gas mark seven and set a timer for 20 minutes. Once 20 minutes is up, reduce your oven temperature to 190°C/170°C fan/gas mark five.
Peter explains why this is the ideal way of cooking a leg of lamb: “You should always begin your roast at a high heat to give it a delicious crispy skin. Reducing the temperature after 20 minutes will let it cook through without drying up.”
How to cook a leg of lamb in the oven
Follow these steps for a perfectly cooked leg of lamb:
Take your lamb out of the fridge and leave it to sit at room temperature for around 30 minutes.
Preheat the oven to 220°C/200°C fan.
Check the packaging of your lamb and make a note of the weight so you can calculate roasting time.
Put your lamb in a roasting tin if it isn’t already, and pop it in the oven for 20 minutes.
After 20 minutes, lower the oven temperature to 190°C/170°C fan and cook for a further 1 hour 45 minutes (based on a medium-cooked, 2kg weight leg of lamb with the bone).
Bring your lamb out of the oven. Use a meat thermometer and insert it into the centre of the leg of lamb and leave for 20 seconds to check if it’s cooked the way you prefer (60-66°C for medium and 67-74°C for well done).
When cooked to your liking, take it out of the oven.
Cover loosely with foil to keep it warm and leave to rest for around 30 minutes before transferring to a serving platter or board for carving.
Peter explains the secret to success when cooking a leg of lamb: “After 20 minutes, lower the temperature and pour a little water or stock into the roasting pan to keep the meat moist. This liquid also makes tasty gravy afterwards!”
“When the leg of lamb is cooked and out of the oven, let it rest for 20-30 minutes to allow some of the flavoursome juices to be reabsorbed into the meat. This also firms it up slightly, making carving a lot easier.”
How to cook a leg of lamb in the slow cooker
Putting your lamb in the slow cooker is one of the easiest ways to cook and you’ll be rewarded with tender meat that falls off the bone. Slow-cooking your lamb in wine and stock keeps the meat succulent, and the sealed lid locks in all the flavour and moisture.
You can marinate your lamb as usual before following these steps:
Set your slow cooker to low.
Heat some olive oil in a large, non-stick frying pan.
Add the lamb and cook for 4-5 minutes on each side.
Place your lamb in the slow cooker and pour in 150ml of red wine and 200ml of lamb or chicken stock.
Put the lid on and cook slowly for around 8 hours or until soft and tender.
Remove the lamb, transfer to a plate, and cover it with foil.
Leave to rest for approximately 30 minutes before carving.
You can also use the liquid left in your slow cooker to make gravy. Simply add to a pan with around two tablespoons of plain flour and mix with a balloon whisk until combined. Then, bring to a gentle boil to thicken for around two minutes. Adding a teaspoon of butter at the end will also give your gravy a silky shine!
Read our guide on how to make homemade gravy from scratch to learn more.
Do you cover a leg of lamb when roasting?
No, you won’t need to cover your leg of lamb when roasting.
Peter explains, “Your roast begins at a high heat to create a crispy skin, so covering your meat will prevent it from browning.” And after the skin has crisped up, turning the oven down should prevent it from burning.
The only time you should cover your lamb is when you’ve pulled it out of the oven and it’s resting.
How do you cook a half leg of lamb?
Cooking half a leg of lamb uses the same method as a full one — it’ll just need less cooking time. Weigh your piece of meat and use our above guidance to see how long it needs in the oven as you normally would.
How do you cook a butterfly leg of lamb?
When a leg of lamb is butterflied, it simply means the meat has been opened and rolled out flat. A butterflied leg cooks more evenly and spices or marinades can be distributed more easily, creating a more flavourful piece of meat. Thanks to the flat surface, it's also ideal for cooking on the BBQ; the perfect treat for a summer's day!
Remove the bone from the lamb.
Lay the meat on a chopping board with the skin side facing down.
Using a sharp knife, cut halfway into the flesh on each side where the meat is thicker.
Then, open it out like a book.
Add your chosen marinade and pop it in the fridge for around three hours.
Remove from the fridge 30 minutes before you're going to cook.
All that's left to do is roast, following the recommended cooking time for the weight of your boneless lamb. Just make sure to flip your lamb, so both sides are evenly cooked.
Or, you could cook on the BBQ for around 20 minutes for a beautifully smoked taste.
How long does cooked lamb last in the fridge?
If you’ve somehow managed to resist eating all your roast lamb or you’re too full after your Sunday dinner (we’ve all been there), don’t throw the leftovers in the bin!
Peter says, “cooked lamb will last up to three days in the fridge if stored in a good quality airtight container. When you come to eat it, ensure you bring it to room temperature first, and I recommend reheating gently in a pan until piping hot.”
Can cooked lamb be frozen?
Cooked lamb can be frozen for up to three months, and it’s a great way to reduce food waste if you’ve lots of leftovers. Meal prepping — also known as batch cooking — with lamb and popping it in the freezer to eat another day can also save you time and money.
To freeze, divide your leg of lamb into portions before putting it in an airtight container or wrapping in cling film. Labelling with the date will also help you keep track of how long it has been in the freezer.
Just make sure your lamb is at room temperature; if frozen when warm, moisture will rise to the top, forming a layer of ice. This could also raise the temperature in the freezer, potentially causing other foods to thaw, altering their taste and texture.
Before you plan on eating, take your lamb out of the freezer and defrost it in the fridge for around 24 hours, depending on the weight. Then, approximately 30 minutes before you cook, bring it to room temperature by taking it out of the fridge. Defrosting your lamb slowly will prevent any harmful bacteria from developing; the outside may appear cooked, but the inside may still be cold!
Can you reheat lamb?
Yes, you can, and there are many ways to do it!
Cooked lamb can be easily reheated on the hob in a non-stick frying pan, but you must ensure you’re not cooking it too fast, as this could dry it out! Bring your pan to medium heat and add a splash of olive oil. Place in your lamb and cook on each side for a couple of minutes until piping hot. You can test your meat using a thermometer; once it reaches an overall temperature of around 60°C, you’ll know it’s ready.
Lamb can also be cooked in a preheated oven at around 150°C for 30-60 minutes, depending on the size of your meat. Pouring a few spoons of stock or hot water over your lamb and wrapping loosely in foil will prevent it from becoming dry and tough.
The microwave is a handy way to reheat lamb quickly. Place on a microwaveable plate, drizzle over a bit of stock and cover to keep your lamb succulent. Cook in 30-second intervals, checking on your lamb and turning it over halfway through to cook evenly. Heating in a microwaveable storage container with a vent is a good option, as this will trap in moisture while letting out necessary steam.
Check out our food storage guide to learn more about picking the perfect container for your leftovers.
How to carve a leg of lamb
Carving a leg of lamb with the bone in can feel intimidating. But with the correct equipment, it doesn’t have to be complicated.
Peter says, “when carving a leg of lamb, ensure you have a long sharp knife and carving fork to hand. A sharp knife will glide effortlessly through meat rather than tearing it. Giving your joint time to rest will also firm it up a bit, making it easier to cut.”
Follow these simple steps:
Cut off the shank end of the leg, where it joins the hip bone.
Stand the leg up on its flat end and slice through the thickest part of the meat, with your knife parallel to the chopping board, until you reach the bone (you can use a carving fork to hold the joint in place while you do this).
Turn the leg over and repeat this process on the other side until you have removed all the meat.
Peter says the key to carving lamb successfully is a sharp knife, so read our guide on how to sharpen a knife to learn more.
What to have with a leg of lamb
A leg of lamb is the main event in a roast dinner and is the perfect choice of meat for special occasions or as a Sunday treat. But what can you pair with it?
But for something a bit different to your traditional roast, Peter recommends, “shred your lamb up and add it to a frying pan with a little olive oil, a sprinkle of cumin, a squeeze of lemon, and a tin of tomatoes to make a delicious quick and easy North African stew.”
A great idea if you fancy cooking something new or for a mid-week meal with leftover lamb!
The best tools for cooking a leg of lamb
Best for roasting: Masterclass Non-Stick Roasting Pan
A kitchen must-have for Sunday dinners: this roasting tin by MasterClass features convenient handles, so you can easily lift the meat out of the tray when you're done roasting.
"This roasting dish is a great size and is really versatile too; not only can you roast joints of meat, it's also great for veggies and potatoes," says Peter.
"Having a rack allows heat to circulate around your joint of meat, giving it a nice crispy skin. As the meat is elevated, the juices can mix with the veggies below, making for a great roast."
You can also use the leftover liquid in your tray to make tasty gravy!
Best for measuring food temperatures: KitchenAid Instant Read Meat Thermometer Probe
“A meat thermometer is not only important for taste but also food safety at home. This is the perfect tool to quickly give you an accurate core reading, so you know when your food is cooked,” explains Peter.
This sturdy KitchenAid thermometer is also shatterproof, so it can withstand any accidental drops to the floor!
Best for resting and carving meat: KitchenCraft Large Chopping Board
"This chopping board is great for catching the meat juices as it rests and when you carve. You can then use those juices in your gravy. It's also a great size to take straight to the table to serve," explains Peter.
It's made from dense tropical hardwood that's renowned for its durability, so you won't have to worry about warping or splitting as long as you look after it!
Enjoy succulent roast leg of lamb today
Whether you’ve got a dinner party in the diary or just want to level up your Sunday roast, a deliciously tender leg of lamb is sure to go down a treat. And with the right tools and technique, achieving succulent lamb that’s cooked to perfection is easy!