Method
Score and season (night before, optional). Use a sharp knife to score the lamb skin in a crosshatch pattern — cuts about 1cm apart, 5mm deep. This helps fat render and skin crisp. Make small incisions and insert garlic slivers and rosemary leaves. Rub with olive oil, salt, and pepper. Cover and refrigerate overnight. Bring to room temp 1 hour before cooking.
Prepare the roasting base. Preheat oven to 160°C (fan-forced). In a large roasting tray, scatter onions and carrots. Place lamb on top, fat-side up. Pour stock and wine around (not over) the lamb.
Roast low and slow. Cover tray tightly with foil. Roast for 4 hours. The low heat breaks down connective tissue whilst keeping meat moist.
Crisp the skin. Remove foil. Increase oven to 220°C. Roast uncovered for 30–45 minutes until skin is golden and crisp. Baste with pan juices every 15 minutes.
Rest and serve. Remove from oven. Tent loosely with foil. Rest for 15 minutes. The meat should be so tender it pulls apart with forks. Serve with pan juices (strained and defatted) as a sauce. Accompany with roasted vegetables or mashed potatoes.
