1. Peel onions and slice.
2. Scrape ginger, peel garlic and wash green chillies. Crush them slightly with a pestle.
3. Heat little coconut oil in a saucepan.
4. Add onions, crushed ginger, green chillies, garlic, curry leaves and sauté till the onions are pink in colour.
5. Add the prawn shells and sauté till shells start changing in colour.
6. Add black pepper, garam masala and turmeric powders.
7. Add water and bring to boil. Cook till the water content in the pan is almost reduced to half.
8. Bring the mixture to simmer. Scum off the dirty forth collected on top.
9. Now add the second extract of coconut milk along with the freshly chopped mint.
10. Reduce the flame and add the first extract of coconut milk.
11. Add the limejuice, salt and cooked shrimps.
12. Serve hot, garnished with a boiled medium prawn hanging down from the soup bowl.