Cut the mutton into 1" square pieces and wash it well. Drain water completely.
Heat oil in a pan or a kadai.
Fry the onions on a low flame, till it becomes golden brown.
Remove the golden brown onions from the oil and spread it on a plate. When it cools, crush it with your hand.
Add curd, ginger garlic paste, 3/4th of crushed fried onion, red chilly powder, green chilly paste, garam masala, 1/2 tbsp shahjeera, chopped coriander leaves, chopped mint leaves, saffron water, salt and remaining part of the oil into the marinated meat and leave for 4-5 hours in the refrigerator.
Now wash the basmati rice well. Cook the rice along with water, salt, whole spices like cinnamon sticks, cardamom, 1/2 tbsp shahjeera and cloves.
When the rice becomes three fourth cooked, remove from flame. Drain out the water completely.
Take a deep bottomed pan, add oil and coat the base well. Spread the marinated mutton on the bottom. Over it add all the rice that has been drained. Upon the rice layer, spread lime juice, 2 pinches of saffron liquefied in hot(not boiling) water, ghee for fragrance and remaining part of the crushed onion, few coriander and mint leaves.
Place a tawa/skillet below the cooking pot while giving dum. Seal the lid of the cooking pot tightly with chapati dough. Dum the biryani for about 15-20 minutes on high flame and for 40 minutes on sim flame. Cover the utensil with a tight lid.
Always take biriyani out from one corner and remember to mix it well from top to bottom.
Serve Mutton biriyani - Hyderabadi Style hot with curd chutney.