Make deep incisions in the mutton leg using a sharp knife to allow the marinade to penetrate.

In a bowl, mix together ginger-garlic paste, yogurt, lemon juice, red chilli powder, turmeric powder, garam masala, coriander powder, cumin powder, and salt to form a smooth paste.

Rub the marinade all over the mutton leg, ensuring it is evenly coated. Let it marinate for at least 2 hours or overnight in the refrigerator for better flavours.

Preheat the oven to 180°C (350°F).

Heat oil in a large oven-safe pan or skillet over medium-high heat. Sear the marinated mutton leg on all sides until browned.

Transfer the pan with the mutton leg to the preheated oven. Roast for 2.5-3 hours, basting occasionally with the pan juices, until the meat is tender and cooked through.

Once cooked, remove from the oven and let the mutton leg rest for a few minutes. Garnish with fresh coriander leaves. Slice the mutton leg and serve hot with lemon wedges.

Cooking time may vary depending on the size and thickness of the mutton leg. It's important to monitor the internal temperature of the meat using a meat thermometer. For a more flavourful roast, you can add additional spices or herbs according to your preference. Accompany the Mutton Leg Roast with roasted vegetables, mashed potatoes, or a side of fragrant biryani rice for a delightful meal.