n n n  Clean the crabs. In a pan, add crabs, finely chopped onion and turmeric powder. Add sufficient water. Do not add too much as you need to over cook it to reduce the water quantity later.n n Cook the crabs over medium flame.n n Meanwhile, in a kadai, add oil, add all dry whole spices mentioned. Add grated coconut, vertically sliced onion,garlic and tamarind.n n On a medium flame, roast these ingredients till the mixture turns brown.n n Let this mixture cool, then in a mixer grinder, grind this to a smooth paste with little water.n n The crabs are cooking simultaneously. Now add Malvani masala powder to it.n n Once the crabs are 80% done, add this ground mixture to the crabs.n n Cook till crabs are done completely. n n Add salt.n n Serve hot with Rice.n n nnn  n