1-First, preheat your oven to 240°C (465°F) to give the lamb a nice sear right from the start. Rub the 1.8 kg bone-in lamb shoulder with 2 tablespoons of olive oil, 2 teaspoons of salt, and 1 teaspoon of black pepper for a simple yet effective seasoning.

2-Next, make twelve deep incisions in the meat without going all the way through, and insert 8 sprigs of rosemary and 3 slivers of garlic into these cuts to infuse deep flavors. Place the seasoned lamb over a base of 1 quartered onion, 1 halved garlic bulb, and extra rosemary sprigs in a roasting pan, then pour 1 cup of water around it to keep everything moist.

3-Once the oven is hot, pop the lamb in and roast at 240°C for a short burst, then reduce the temperature to 180°C (350°F) and cover it for 3 hours. This slow roast allows the meat to become tender and juicy.

4-After that, uncover the lamb, crank the oven up to 220°C (425°F), and roast for another 20-30 minutes until the skin is crispy and browned.

5-Finally, let the lamb rest covered for at least 20 minutes to lock in juices and improve tenderness.