Marinate prawns with turmeric powder, pepper powder, chilli powder, garam masala powder, lime juice and salt and fry it in oil.
In the same oil used for frying prawns, add sliced onion and split green chillies and saute it till the onion becomes light brown.
Add ginger-garlic paste and fry for 2 mins.
Add sliced tomato, 1/2 cup chopped mint leaves, 1/2 cup chopped coriander leaves, turmeric powder, garam masala and salt.
Saute till the masala get mixed well.
Add the fried prawns along with little water and cook the curry in a medium flame until the gravy thickens and remove from fire.
Wash and soak basmati rice for 2 hours and then drain it.
Heat 4 tbsp of ghee in a heavy bottom pan and fry cashew and raisins and remove it from the ghee.Then fry the sliced onion till it is golden brown and crispy and keep it aside.
Add drained rice in this ghee, fry for 5 mins and add 4 and half cups of boiled water along with salt, cardamom, cinnamon and bay leaves.
Cook till the rice is done and the water is evaporated completely.
In a large heavy bottom vessel, spread the prawn masala first and layer the rice over it.
Sprinkle the remaining 2 tsp garam masala over the top of the rice layer, sprinkle pineapple essence and saffron mixture.
Put chopped mint and coriander leaves, fried cashews, raisins and spread it over.
Cover it tightly with a lid and keep on low flame for 15 mins.
:15) Serve hot with salad, pickle and papad.
Sprinkle the fried onions over the biryani while serving.