Marinate the mutton with ingredients starting from ginger-garlic paste to fried onions (leave aside 1/4 cup fried onions and 2 tbsp. coriander and mint leaves) for 4-5 hours preferably overnight.
Boil sufficient water in a pan and add the rice, salt to taste, cinnamon, cardamoms and cloves. Cook till it is half done. Drain and keep aside.
In a heavy bottomed pan or a pressure cooker, add the marinated mutton and top it up with a spread of the rice. Sprinkle the remaining fried onion, coriander-mint leaves, ghee and saffron milk.
Cover with an aluminium foil tightly around the edges and place a lid on it. Cook on a high flame for 2-3 minutes. Then place the cooker on a hot tawa / griddle and cook on a very low flame for 45 minutes. Switch off the flame and let it remain covered for another 5 minutes. Serve this delicious Biryani along with raita, sliced onion, lemon wedges and green chilies.