1-First, preheat your oven to 240°C (465°F) or 220°C (425°F) if using a fan-forced setting. It’s all about getting that initial blast of heat to start the process right. Rub the lamb shoulder with 2 tbsp olive oil, 2 tsp salt, and 1 tsp black pepper for a flavorful base.

2-Next, make 12 deep incisions in the lamb without going all the way through, and stuff those with the rosemary sprigs and garlic slivers. Place the quartered onion, halved garlic head, and any remaining rosemary in the base of your roasting pan, then set the lamb on top and pour 1 cup water around it.

3-Cover the pan with a lid or foil and roast at a lowered temperature of 180°C (350°F) or 160°C fan-forced for 3 hours. After that, uncover, check the liquid, and add about ¾ cup water if needed, then crank the heat back to 220°C (425°F) for 20 to 30 minutes to crisp the skin.

4-Once done, test the meat with two forks; if it’s not tender, cover and return to 180°C until it pulls apart easily. Let it rest for at least 20 minutes covered with foil and tea towels. For the gravy, keep 2 tablespoons of fat in the pan, stir in flour, add beef broth or the wine mixture, simmer for 1-2 minutes, season, strain, and serve. The total prep time is just 15 minutes, with a cook time of 3 hours 30 minutes, making the whole process about 3 hours 45 minutes.