How To Roast Lamb: Cooking Times & Tips

Fancy a proper Sunday roast? You've come to the right place! This cooking guide will show you how to cook roast lamb perfectly every time, whether you're a seasoned pro or a first-timer. We'll help you choose the best cut of lamb for roasting, share tips on how to prep it, and then take you through a simple step-by-step cooking method.

But that's not all! We've also got tips for serving up a feast and even some cracking ideas for using leftover lamb (if you have any!). So, get ready to impress friends and family with a truly delicious roast lamb dinner – it's easier than you think!

What is the Best Cut of Lamb for Roasting?

Want to know the secret to a knockout roast lamb? It all starts with choosing your cut! When picking your piece of lamb, consider the fat content. Generally, more fat means more flavour, while leaner cuts are healthier as they contain less fat. Also, consider whether you prefer bone-in or boneless cuts, as bone-in adds flavour, while boneless cuts are easier to carve.

Now, let's explore the lamb cuts best suited for roasting so you can cook up a proper Sunday (or any day!) roast…

Leg of Lamb

This is a real crowd-pleaser. It's a large joint that's good for feeding a big family. You can choose a bone-in leg for extra flavour or a boneless one if you want easier carving. Just remember, it's leaner, so don't overcook it.

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Shoulder of Lamb

For maximum tenderness and flavour, the shoulder is the way to go. It's got more fat, which keeps it juicy and delicious, especially with slow roasting. Bone-in is a classic choice for a traditional roast.

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Rack of Lamb

If you want something a bit special, a rack of lamb is a great option. It looks impressive and cooks relatively quickly. But it's leaner, so take care not to dry it out.

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Lamb Breast

The most fatty of all the joints, the breast is under-used and underrated. When boned and rolled around a dry, lean stuffing, it produces a beautifully flavoured, tender and inexpensive roasting joint.

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How to Prepare Lamb for Roasting

Achieving a perfectly roasted lamb, tender on the inside and beautifully browned on the outside, starts with proper preparation. Once you've chosen your preferred cut, these straightforward tips will give you the essential techniques to get your lamb ready for the oven and guarantee a delicious and succulent meal.

Trim your cut

First, trim your piece of lamb by cutting away any large chunks of excess fat with a sharp knife. This will help the meat cook evenly and prevent it from swimming in too much fat!

Marinate overnight

If you like, a marinade will seriously boost the flavour. Indian or Moroccan spices always work well with lamb, rub it all in and let it sit for at least an hour (or overnight in the fridge for the best results). Alternatively, try this winning combo of a good glug of olive oil and stud the meat with a few cloves of garlic and rosemary sprigs.

Ready to cook?

Take your joint of meat out of the fridge an hour before you want to start cooking. This allows your lamb to cook evenly throughout and gives you a more succulent roast. Then, generously season the lamb with sea salt and freshly ground black pepper, ensuring that every part is evenly coated.

Finishing touches

Place the lamb in a decent-sized roasting tray to catch all those lovely juices for your gravy. For added flavour, you can add some chopped veggies to the bottom of the pan too.

Step-by-Step Guide to Cooking Roast Lamb

You might be surprised at how easy it is to roast lamb to perfection! Just follow these straightforward steps for guaranteed success every time.

1. Calculate your cooking time

First, preheat the oven so that your lamb cooks evenly. For large joints, cook them on high heat (220°C / gas mark 8) for the first 20 minutes to give you that lovely crisp skin. When roasting, remember that the cut dictates the cooking time. Leg, shoulder, and rack of lamb each have a different amount of time in the oven for best results. Here’s a rough guide you can follow to calculate your lamb cooking times:

Cut	Temperature	Time
Whole, Half or Boneless Shoulder	170°C / 150°C Fan / Gas 3	40 minutes per 500g, plus 40 minutes
Half or whole leg	180°C / 160°C Fan / Gas 4	Medium - 25 minutes per 500g, plus 25 minutes Well done - 30 minutes per 500g, plus 30 minutes
Part-boned shoulder	180°C / 160°C Fan / Gas 4	60 minutes per 500g, plus 30 minutes
Lamb Rack	190°C / 180°C Fan / Gas 5 Or if frying first: 200°C / 180°C Fan / Gas 6	Cover bones with foil and cook for: 20 minutes per 500g, plus 20 minutes. Or for a faster option: Preheat a nonstick frying pan and fry the lamb on all sides over a high heat to seal then transfer to a small roasting tin and cook for: Medium - 14 minutes Well done - 16 minutes
Breast	180°C / 160°C Fan / Gas 4/5	30 mins per 450g, plus 30 minutes
Topside Joint	200°C / 190°C Fan / Gas 6	Medium - 20 minutes per 500g, plus 20 minutes. Well Done - extend cooking time.

2. Baste for flavour

Baste the meat 2-3 times during cooking. Using a turkey baster or a large spoon, scoop the juices up from the corner of the pan, and drizzle back over the top of the joint.

3. Check on your roast

A thermometer is the best way to guarantee perfectly cooked lamb, insert it into the thickest part of the meat, away from the bone. The internal temperature should reach at least 63°C as this is the minimum safe internal temperature.

Alternatively, Pierce the thickest part of the joint to check if it’s ready. Pinky-red juices mean it’s rare, slightly pink is medium, and clear juices mean it’s well done.

You can follow along with the video below, where our very own Morrisons chef Jon Coates shows you how to get the perfect flavoursome result, crisp skin and a juicy middle.

Roast Lamb Serving Tips

Alright, your roast lamb is cooked to perfection – brilliant! Now, let's make sure it's served up in style. First off, and this is a must, give it a good rest! Cover it with foil and leave it for at least 15 minutes before carving. This makes your lamb much more tender and succulent, trust us.

When it comes to carving, how to serve roast lamb depends on what cut you've got. For a leg or shoulder, slice it against the grain – that's across the muscle fibres, not with them. For a rack of lamb, you can carve between the ribs to serve individual chops.

And finally, let's talk sides! To make your meal a hit, think about what to serve with roast lamb. You can't go wrong with classic side dishes like creamy mashed potatoes, crispy roast potatoes, and plenty of vibrant green vegetables. Or, if you're looking for something a bit more adventurous, take some inspiration from our What to Have with Lamb guide.

What to do with Leftover Roast Lamb?

What about those leftovers? Don't let them sit lonely in the fridge! Leftover roast lamb is your secret weapon for quick and easy family dinners. Just remember to store it right! Get it cooled down and straight into an airtight container in the fridge ASAP. You can store it for up to 3 days, ready to be turned into something spectacular.

Now, let’s get creative! There are loads of leftover roast lamb recipes to choose from. How about a hearty lamb and sweet potato pie? Or maybe some tasty lamb tacos with all the trimmings? You could even try a warming lamb curry. The possibilities are endless! So, get inspired and give your leftover roast lamb a second life. The whole family will love these delicious lamb leftover recipes.

Leftover Lamb Nachos

Lamb Tagine & Sweet Potato Pie

Lamb Birria Tacos

Lamb Dhansak

Time to Enjoy Your Roast Lamb

So there you have it – your complete guide to cooking a lamb roast like a pro! From choosing the perfect cut to serving up a feast, you're now armed with all the know-how you need. With a little practice, you'll be whipping up stunning lamb dishes that everyone will rave about. Left wanting more more meal ideas? Check out our roast dinner recipes and lamb recipe collections.

Don't forget to grab all your ingredients in-store or online and get creative! Don't forget to share your masterpieces with us on social media using the #MorrisonsRecipe – we love to see what you've whipped up!