Thoroughly wash the prawns. Add turmeric powder, curd, one spoon red chilly powder, lemon juice and one tea spoon salt. Mix well and leave to marinate.
Take all the ingredients for preparing spicy paste in a blending jar and prepare a smooth paste ( spicy paste.).
Add oil to a deep bottomed frying pan and heat. Add the cashew nuts and fry. Add the marinated prawns and fry till oil shows up. Add grated coconut and half split green chillies and fry till the raw smell is gone.
Add the onion pieces and fry till they are brown. Add tomato pieces and simmer in medium flame till the tomato pieces are smooth.
Add the remaining red chilly powder, sufficient salt and the spicy paste. Stir fry till the spicy paste is fried deep brown. Add two cups of water and mix well.
Allow to simmer in medium flame till all the ingredients are blended with each other and the prawns are cooked well.
Finely chop the coriander leaves.
Spread the finely chopped coriander leaves on the curry and serve hot.