1. Shell prawns and remove intestines, wash well.
2. Rub some salt on prawns. Keep aside.
3. Grind garlic, ginger, and green chillies.
4. Heat oil, fry chopped onions, ground garlic and ginger, chilli powder, coriander powder and curryleaves.
5. Add prawns and chopped tomatoes, cook on a slow fire.
6. Grate coconut and extract milk.
7. When prawns are cooked, add vinger and coconut milk. Bring to boil and remove.
8. Serve hot with rice.