Roast coconut in a pan to brown color n let it cool dwn.... Blend tomatoes, roasted coconut, garam masala, fish masala, corriander powder, chilli powder, salt, garlic paste, tomato puree n turmeric powder to a fyne paste
In a pot braise onion in 3-4 tbsp oil til its browned up...
add coconut paste, chopped garlic n let it boil add lil water n crabs, cook til done.
add tomato mixture n water, let it cook til done...
Simmer to make thick roast...
Garnish wid chopped corriander leaves n green chillies....