Soak Basmati Rice for 30 mins. Marinate the prawns for some time with ginger garlic paste, salt, chili powder and coriander powder.
Boil water for the rice. When the water just starts to boil, add oil, salt, shahi jeera(Black cumin seeds), cloves, cardamon, cinnamon, black pepper and a bay leaf. When the water is boiling well, add rice. The rice should be cooked till it is 85 to 90% done. Drain and keep aside.
Heat oil. Add cardamon, cinnamon, cloves, mace and cumin seeds. When they start spluttering, add the prawns and fry. Add prawns bit by bit. If all the prawns together they will leave a lot of moisture, and then instead of frying, the prawns will boil and we want the prawns fried, not boiled. Fry for around 3 mins or till 50% cooked.
Remove the prawn and retain the oil in the same vessel. To this oil, add curd, and mix it well. Next add chopped green chillies, coriander leaves, mint leavers, salt, biryani masala and fried onions.
Then add the prawns and mix well once. Spread it in the dish. Add the rice on it and spread. Sprinkle coriander leaves, fried onion, garam masala powder(cloves, cinnamon, cardamon and black pepper) and saffron diluted in water.
Cover with an air tight lid and cook on low flame for around 7-10 mins.
When done, mix well and serve hot.