Soak tamarind in 1/2 cup of hot water for 10 minutes. Remove the seeds and keep the water aside. Grind the green chilies, garlic and cumin seeds to make a paste.
Heat oil in a pan and fry the onions until soft and add the ground chili-garlic paste and fry for further 2 minutes. Put in the tomatoes and fry until soft. Then add all the spice powders and stir-fry for a minute. Add half of the tamarind water, Jaggery, salt, curry & cilantro leaves. Pour 1/2 cup of water and bring it to a boil. Simmer for 5 minutes. Now add the shrimp and cook until they are completely cooked and the gravy becomes thick. Serve hot.