Step 1: Marinate the Prawns
In a bowl, combine the prawns with red chilli powder, turmeric powder, black pepper, ginger-garlic paste, lemon juice, and salt. Mix well and set aside for 20–30 minutes.
Step 2: Cook the Prawns
Heat a little coconut oil or ghee in a wide frying pan. Add the marinated prawns and cook over medium heat for 2–3 minutes on each side, just until they turn pink and lightly golden. Remove from the pan and keep aside. Avoid overcooking, as prawns become firm very quickly.
Step 3: Prepare the Masala
Heat the remaining coconut oil or ghee in a heavy-bottomed pot or biryani handi. Fry the sliced onions until golden brown, then transfer half to a plate for garnishing. Add the ginger-garlic paste, green chillies, and chopped tomatoes. Cook until the tomatoes soften.
Stir in the curd or coconut milk, coriander powder, Malabar biryani masala, and salt. Cook for a few minutes until the masala comes together. Gently add the cooked prawns and half of the chopped mint and coriander leaves. Mix carefully to coat the prawns without breaking them.
Step 4: Cook the Rice
Wash and soak the Jeerakasala (Kaima) rice or aged basmati rice for 20–30 minutes. Bring plenty of water to a boil with the whole spices, salt, and ghee. Add the soaked rice and cook until it is about 70–75% done. Drain well.
Step 5: Layer the Biryani
Spread half of the prawn masala evenly over the base of the handi. Cover it with half of the partially cooked rice. Repeat with the remaining masala and rice. Top with the reserved fried onions, saffron milk, fried cashews, fried raisins, a drizzle of ghee, and the remaining mint and coriander leaves.
Step 6: Cook on Dum
Cover the pot with a tight-fitting lid. If desired, seal the edges with atta dough or place a clean kitchen cloth under the lid to help retain the steam. Cook over low heat for 20–25 minutes.
Step 7: Rest and Serve
Turn off the heat and let the biryani rest for 10 minutes before opening the pot. Gently fluff the rice with a fork or slotted spoon and serve hot with raita, pickle, papad, or your favourite side dish.