Add the chilli powder, turmeric and salt and tandoori masala to the prawns and keep aside.
Heat oil in a flat bottom pan. Add the whole masala and let it crackle. Add ginger garlic chilli paste and fry for a minute. Add onions and fry till translucent. Add the washed rice and fry for five minutes on low flame. Add the prawns along with its masala and fry for a minute.
Add 4 cups of hot water. Cover and cook till rice is done.