1. For the prawn masala:
2. Grind together all ingredients with vinegar.
For the curry:
3. Dust the prawns with turmeric and salt. Keep aside.
4. Then fry onions until light brown.
5. Add ground masala and fry. Add prawns and fry until pink.
6. Then add some coconut milk and bring to a boil.
7. Simmer for 5 minutes and garnish with green chillies.