Heat 3 tbsp oil in a vessel and add the chopped onions and green chillis and fry till transparent.Add the ginger garlic paste and fry till oil seperates.
Add all the powders and mix well.Add the tomatoes and stir fried drumstick pieces and cook further for another 3-4 minutes.
Add the prawns and stir well till its well coated with the masala.Let it cook for 2 minutes and then add the coconut paste and salt and add 1 cup of water.
Cook covered for 5 minutes till you get the desired curry consistency.Turn off heat.
Garnish with chopped coriander leaves and serve hot with steamed rice or rotis.