Australian-Style Roast Leg of Lamb | Sunday Roast with Rosemary and Garlic

Take the leg of lamb out of the refrigerator 1 hour before roasting. Use the tip of a knife to make slits 2 cm deep in the thick parts; make twelve slits in all. Push one garlic slice and one pinch of rosemary leaves into each slit. Pat the surface thoroughly dry with paper towels; wet meat steams instead of browning. Rub all over with olive oil, salt, and black pepper.

Preheat the oven to 230°C / 445°F. Place the lamb on a wire rack in a deep roasting pan, fat side up, and roast for 18 minutes. A brown, dry crust should form; it adds flavor and slows moisture loss during the longer roast.

Remove the pan from the oven. Arrange the potatoes, carrots, and onion, cut into large pieces, underneath the lamb at the bottom of the pan. Pour in 200 ml of broth. Reduce the oven temperature to 160°C / 320°F. The vegetables serve as a side and catch the drippings that form the base of the sauce.

Roast at 160°C / 320°F for 70 minutes. Insert a thermometer into the thickest part of the meat without touching the bone: 60°C / 140°F is the target for a pink result and 68°C / 155°F for well-done. The internal temperature rises another 3–4°C / 5.4–7.2°F while resting, so remove the lamb before it reaches the target. If the pan dries out, add 100 ml of hot water.

Transfer the lamb to a board and cover with foil. Move the vegetables from the pan to a bowl. Spoon off most of the fat from the remaining liquid, leaving 3 spoonfuls in the pan. Set the pan on the stove, add the flour to the fat, and cook, stirring, for 2 minutes. Gradually pour in the remaining broth, whisking until smooth. Boil for 6 minutes, then add the apple cider vinegar and the resting juices from under the lamb. Strain into a gravy boat and slice the lamb across the grain.