Clean crabs and wash thoroughly. Detach and crack the claws. Cut each into 2 pieces. Peel and finely slice onions and ginger.
Peel garlic. Clean, wash and finely chop fresh coriander leaves. Soak tamarind in one cup warm water for 1/2 hour, remove the pulp, strain and keep aside.
Heat 1 tablespoon oil in a pan and pan-roast sliced onions, sliced ginger, scraped coconut and garlic till light golden brown.
Remove from heat and cool. Add a little water and grind to a thick paste.
Heat remaining water in a pan, add mustard seeds and when they start crackling add curry leaves. Add masala paste, cook on medium heat for 1/2 minute, stirring continuously.
Add turmeric powder, dry Malwani masala, red chilli powder, tamarind pulp and salt. Stir well and add 1 cup of water. Bring it to a boil and add crab pieces and claws.
Cook further on medium heat for 10-15 minutes, stirring continuously or till the gravy becomes a little thick. Serve hot, garnished with fresh coriander leaves.
