A classic roast lamb leg with a flavour packed gravy. Get the best lamb you can afford, and I really urge you to get a meat thermometer (even a cheap $5 one from Ebay which is what I have!) so you're guaranteed a juicy, perfectly cooked lamb every single time! Watch the cooking video below the recipe to see how easy this is to make!
Author: Nagi | RecipeTin Eats
2.25 kg / 4.5lblamb leg, bone in
1 1/2tbspfresh rosemary leaves, finely chopped*
3garlic cloves, minced*
Salt and pepper
2whole heads of garlic, halved horizontally (Note 1)
Few sprigs rosemary *
4 tbsp / 50gflour
2 1/2 cups / 625 mlbeef broth / stock (Note 2)
Take lamb out of fridge at least 1 hour before roasting. (Note 2)
Rub: Combine rosemary, garlic and olive oil. Mix and set aside for 20 minutes+.
Preheat oven to 220C/430F (fan forced / convection) (Note 3) with oven shelf in the middle.
Place garlic cut side up in a roasting pan. Toss in rosemary sprigs.
Turn the lamb over so the underside is facing up. Pour half the Rub on, add a good sprinkle of salt and pepper. Rub all over.
Transfer into roasting pan, placing it on the garlic to elevate the lamb. Rub remaining rub + salt and pepper over lamb.
Roast lamb for 20 minutes then turn down to 180C/350F (fan forced/convection) (Note 4). Roast for 1 hour - total of 1 hr 20 minutes.
Remove lamb from oven. The internal temperature should be 55 - 60C/131 - 140F for medium rare (pictured). This will rise to 61 - 65C / 142 - 151F after resting. See notes for cook times - Note 5.
Transfer lamb to plate, cover with foil and rest for 20 - 30 minutes.
Make gravy straight away while roasting pan is hot.
Remove rosemary sprigs. You should have around 4 - 5 tbsp of fat. If less, add butter. If much more, discard a bit.
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.
Pour in half the beef stock and mix to dissolve sludge in, then add remaining beef stock and mix.
Use a potato masher (if you're really keen like me) to mush the garlic to squeeze out the flavour.
Add salt and pepper to taste.
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 boat.
* These are optional. It adds flavour to the skin but not an enormous amount for a lamb roast of this size.1. The garlic elevates the lamb 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 the garlic cut side up so the flavour infuses into the flesh of the lamb. You could put the lamb on a rack and put the garlic under the rack. You can use onion instead of or in addition to garlic. It is not garlicky at all because when garlic roasts, it becomes sweet and caramelised. It is my big secret for making gravy! 2. 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 rocks! If you cannot consume beef for religious or health reasons, then chicken broth can be substituted.3. Bringing a lamb leg to room temperature before roasting makes a huge difference for more even cooking. Cold lamb leg = overcooked on the outside by the time the inside is cooked.4. Oven temps for standard / no fan ovens: Initial high temp to start the browning at 240C/465F, then lower to 200C/390F for the remaining cook time.5. INTERNAL TEMPERATURE of cooked lamb: Medium rare (blush pink inside, as pictured): Temp out of oven 55-60C/131-140F. This will rise to 61-65C / 142-151F after resting. Medium (barest hint of pink inside): out oven: 60–66°C, after resting: 66–70°C Well done (least juicy, no pink at all): out of oven: 67–71°C, after resting: 71–75°CCOOK TIMES - refer to the table below the recipe. I highly recommend getting a meat thermometer for accuracy - only guaranteed way to get juicy lamb every time!6. The lamb leg will stay warm for up to 1 hour. The inside is still warm even after 3 hours. For my Sunday Roast Lunch, I roasted the lamb legs separately before my guests arrived, and the first lamb leg was still warm inside when I served it at 1.30 (I took it out of the oven at 10.30 am). The crust wasn't that warm, but it didn't really matter because even if the lamb leg was hot, once sliced thin and served, the slices lose heat quickly. The warmth comes from the gravy!So if you want roast veggies or Truly Crunchy Roast Potatoes, it's fine to make them while the lamb is resting. I don't recommend roasting at the same time in separate roasting pans because it will reduce the heat of the oven and you'll end up compromising both the veggies AND lamb. And if you roast the lamb ON veggies, then you won't have enough drippings for gravy.7. Servings: A 2.25 kg lamb serves 6 very generously and 8 comfortably. The bone is around 400 - 500g, leaving around 1.8kg of meat. This shrinks to around 1.5 kg after cooking. 250g lamb per person for 6 / ~200g for 8 is sufficient - remember the lamb is sliced so it makes it seem like there is more!8. Nutrition per serving, assuming 8 servings and that all the gravy is consumed.