Roast Lamb Leg with Gravy

4.99 from 50 votes

Recipe video above. I love a roast lamb leg! My top tip is to use a meat thermometer. There's no way to guarantee perfect blushing pink roast lamb without one, even if it's a cheap one!

Rubbed with rosemary garlic and accompanied with a killer gravy for lamb. Serve with peas, buttered steamed carrots and crunchy roast potatoes (either classic or ultra crunchy duck fat potatoes).

Prep Time5

Cook Time1 40

De-chilling and resting time1 30

Total Time15

Course: Dinner

Cuisine: Aussie, British, New Zealand

Keyword: Roast Lamb Leg

Servings: -8

Calories: 450cal

Author: Nagi | RecipeTin Eats

Ingredients

2.75 - 3 kg / 5.5 - 6 lb lamb leg , bone-in (Note 1)
1 1/2 tsp cooking salt
1/2 tsp black pepper

Rub

1 1/2 tbsp fresh rosemary leaves , finely chopped
3 garlic cloves , finely minced
2 tbsp olive oil

Base

2 whole heads of garlic , halved horizontally (Note 2)
Few sprigs rosemary (optional)

Gravy

4 tbsp flour , plain/all purpose
2 1/2 cups beef broth / stock , low sodium (Note 3)

Cups - Metric

Instructions

Take lamb out of fridge at least 1 hour before roasting. (Note 4)
Preheat oven to 240°C/475°F (220°C fan) with oven shelf in the middle.
Rub - Mix rosemary, garlic and olive oil.
Prepare lamb - Place lamb leg in a roasting pan. Coat with the rub using your hands, the sprinkle with the salt and pepper. Place garlic and rosemary sprigs underneath the lamb, garlic cut face up.
Roast lamb leg for 20 minutes. Turn the oven down to 200°C/400°F (180°C fan) and roast for a further 1 hour or until the internal temperature reaches 53°C/127°F for medium rare (Note 5 other doneness). Check first at 45 minutes - everyone's oven is different!
Rest - Remove lamb from oven. Transfer lamb to plate, loosely cover with foil and rest for 20 minutes to 1 hour (it will still be warm enough for serving!). The internal temperature will rise to 62°C/144°F (medium rare). Make gravy while lamb is resting - below.
Serve lamb with gravy, duck fat or classic crunchy roast potatoes, peas and steamed carrots tossed with butter and parsley.

Gravy for roast lamb leg

Drippings in pan - Discard rosemary sprigs. You should have around 4 - 5 tbsp of fat (drippings). If less, add butter. If much more, discard a bit.
Add flour - Place roasting pan on stove over medium heat. When the fat starts to bubble, then add flour. Mix flour in and cook for 1 minute.
Stock - Pour in half the beef stock and mix to dissolve sludge in, then add remaining beef stock and mix.
Garlic squidging - Use a potato masher (if you're really keen like me) to mush the garlic to squeeze out the flavour (also helps flour caught in garlic to dissolve).
Taste - Check salt and pepper (I don't add more).
Thicken - Simmer for a couple of minutes, stirring, until it starts to thicken. Take it off the stove BEFORE the gravy is the thickness you want because it will keep thickening.
Strain into a bowl, mushing garlic to squeeze all the liquid out. Then pour into gravy jug and serve with lamb!

Notes

1. Lamb leg - Recipe is based on a whole lamb leg. See roasting time table above for different lamb sizes. Sometimes the bone sticking out is removed, sometimes it is partially cut so it folds inwards. It doesn't matter either way, but just ensure the bone inside the meat is not removed. (If it is, you have a butterflied lamb leg - use this recipe instead).

Boneless lamb - I love making Greek butterflied lamb leg. If yours is rolled and tied, you could make this recipe but the meat is not quite as juicy because it's been cut to remove the bone so there's more escape roots for meat juices! If you can, unroll the lamb to do the rub then roll it back up and tie again (excellent flavour infusion!). Also, cook time likely a bit shorter. I'd do the 20 minute high temp blast, lower oven then check at 40 minute mark.

2. Garlic base - Elevates the lamb slightly so it cooks more evenly and allows the fat to drip over the garlic so the flavour infuses into the drippings that then forms the base of the gravy. Place garlic cut side up so the flavour infuses into the flesh of the lamb.

It is not garlicky at all because when garlic roasts, it becomes sweet and caramelised. It is my big secret for making a killer gravy for roast lamb! You can use 1 onion, quarters (skin on) instead of or in addition to garlic.

3. Gravy for lamb is best made with beef stock/broth because it has a deeper flavour and makes the gravy a beautiful dark brown colour. Store bought is fine, though homemade makes it ultra restaurant-worthy! If you cannot consume beef for religious or health reasons, then chicken broth can be substituted.

4. De-chilling lamb will make it cook more evenly. Cold lamb leg = overcooked on the outside by the time the inside is cooked.

5. Internal temperature of cooked lamb leg:

Roast lamb leg internal cooked temperature

I highly recommend getting a meat thermometer for accuracy - only guaranteed way to get juicy lamb every time!

6. Holding - The lamb leg will stay warm for up to 1 hour, enough time to make duck fat or classic crunchy roast potatoes! The inside of the lamb is still warm even after 3 hours.

7. Servings: A 2.5 kg/5 lb lamb serves 6 very generously and 8 comfortably. After taking into account the bone (500g/1lb) and meat juices lost during roasting, you should end up with around 1.7kg meat after cooking which is around 280g for 6 people (generous!) or 200g for 8 people. If you slice lamb thinly it will go further!

8. Nutrition per serving, assuming 8 servings and that all the gravy is consumed.

Nutrition