If you let this Slow Roast Lamb Leg take it's place at your Sunday lunch table, you will not be sorry! It's definitely on the easy side of cooking but it does require a little of your time, which is well worth it.
Looking for a slow cooker lamb leg recipe instead? 3 Ingredient 7-Hour Slow Roast.
Slow Roast Lamb Leg
This is what I know for sure about cooking lamb. No matter the method that you use to cook lamb it really is a very 'cook friendly' type of recipe so there are hardly any mistakes in other words. You can perhaps not cook the lamb long enough! Can you imagine that in cooking you've always been told 'don't overcook something' and now I am saying, don't undercook the lamb roast? And it's true. If you you don't give lamb enough time to cook it will be tough or if the oven is too high, it will be tough.
That's not difficult at all, because what it means is, give the lamb roast time and patience and it will reward you with tender beautiful lamb roast.
This lamb roasts for 3 to 4 hours and is between medium to medium well, reading an internal temperature of 65°C(145F) to 70-75°C (160-165F). Which means the meat is definitely tender but not fall apart.
For a slower roast and much more tender meat you can oven roast it for roughly 6 hours and this will give you in internal temp of 80°F /175°F. About 40 minutes per 500 grams.
You can roast lamb with a simple salt and pepper seasoning and a drizzle of olive oil. You can also use a small knife to make small cuts in the meat and insert fresh herbs and spices into the small cuts. In the image above, I stuffed fresh rosemary tied in small pieces of bacon. The cooking method is the same and the full recipe card can be found below.
Ingredients For This Slow Roast Lamb Leg
- Leg of lamb, bone-in
- Olive oil
- Lamb spice rub I used this one.
- Beef stock
How To Make Slow Roast Lamb Leg
A few simple steps and once your lamb is in the oven, your work is done which is wonderful because you can get on with making your side dish. The oven does all the work for you, this lamb roast truly is worth it.
Is it necessary to roast over a rack?
No. You can also prop your roast directly over some vegetables. Why?
- to create a bed for the meat (even cooking)
- and the start of a flavorful gravy (if you want it)
What type of vegetables can you use?
You are not tied down to garlic and onions when creating a bed in preparation for a gravy, however the onions are good because of their size. For a bit of an adventure when you are wanting roast veggies you can also stack them up in a roasting dish and place your roast directly over the oven rack. As seen here in this pork belly video.
- celery stalks
- herbs - rosemary and bay leaf
If you want to make your own gravy by using veggies in the tray then add all the veggies, sit the roast on top and add the liquid.
Adding The Liquid
Why is adding any liquid important?
This lamb roast stays for hours in the oven and even though the heat is low you dont want a dry roast. The liquid adds moisture and moisture = tender meat!
You add about 2 to 3 cups of water. Three being the quantity of choice for me because I use one oven temperature and let the roast go on for hours without interruption. No need to check the water level when you use 3 cups of water and beef stock on low heat. Yes a combination of both - water and stock.
Thawing The Meat
Make sure it's out the fridge way before hand. Depending on the size you have to give it time to reach room temperature. This roast came out the freezer a day before into the fridge, left in the fridge overnight and then the next morning onto the sink to further thaw properly.
The 2nd leg of lamb roast was fresh (no freezing) so from the fridge onto the sink to reach room temperature an hour ahead of cooking.
When meat roasts are thawed properly they create 'even cooking' which helps the meat to cook the same throughout.
Seasoning - Probably the most important after the oven temperature.
Olive oil - use a little to rub the roast all over with the spices.
Beef stock and water - to pour into the tray from the side of the roast. No tampering with the seasoning once it's on or pour the liquids in first and then place your roast on the rack.
And that's it! We use a rack in this recipe to place the roast over so that it doesn't sit on the base of the tray. We need the meat to roast all around. In saying that, as long as you have the roast sitting on a tray if it sits a little in the liquid its really okay.
As a matter of fact I find that when it sits a little in the water it's very tender! The meat being tender needs moisture yes but it also needs the right oven temperature and covering the meat while it roasts.
- water and/or stock (liquid)
- oven temperature
- resting the roast
You are going to cover the lamb with foil before it goes in the oven. Get a sheet of foil over, and roast on the middle rack for a good 4 hours depending on the size. It does need to go back inside for browning, uncovered but not for long.
Resting The Lamb Roast
Resting the meat is essential and 30 minutes is a good amount of time for meat resting but if you can't, then 20 minutes. I've done 10 to 15 minutes when the family can't wait and I get them to set the table. Keep them busy while my roast rests another 5 minutes😍
This step is important because it allows the juices to redistribute themselves back into the roast instead of flowing all over the platter when you cut into it.
Looking For More Recipes?
Slow Roast Lamb Leg Complementary Sides
A few complementary sides to serve your slow roast lamb leg. I love a side of either spicy rice, creamy risotto or in terms of salad, then this Greek salad or this Chickpea salad. Naturally a side of roast potatoes seems to go without saying since they are so loved!
Keep the pan juices and drippings from the roast to make a gravy or make your own gravy without drippings.
A wonderfully simple slow roast lamb leg that you will love and make repeatedly because it's dependable and such a show stopper at your table!
Slow Roast Lamb Leg
- 2kg kg leg of lamb, bone in
- 3 tbsps. olive oil, as needed
- lamb seasoning dry rub - Smell and Taste
- 3 cups beef stock (low sodium) You can also use water.
- 2 cups water
- Heat the oven to 160/170 degrees Celsius.
- Season the well thawed at room temperature lamb with lamb spice and olive oil. Season it all round - top and bottom.
- Place a rack on the oven tray (if it doesn't come with one) See notes below
- Pour the water and stock into the pan.
- Place the roast over the rack. If it's touching/sitting in the liquid a little it's fine.
- Cover the whole tray (and roast) with foil and roast for 3 to 4 hours or until an instant read thermometer reaches 65°C (145F) to 70-75°C (160-165F) a medium to medium well result.
- Remove the roast from the oven, take off the foil and return the roast to the oven. Turn the heat up to 180°C and let it roast for 15 minutes or until the top is a nice golden brown. Make sure the tray is not too high up, you want an even golden brown on top.
- Take the roast out, use a spoon to baste it with the liquid pan juices. Place the leg of lamb roast on a platter to rest for 30 minutes while covered in foil.
- Slice or fork and serve with the pan juices.