Marinate the fish pieces with a pinch of salt, turmeric powder and red chili powder for 10 minutes.
Heat oil in a pan and fry the fish pieces and the radish separately. Drain and keep aside. Temper the same oil with shahjeera, cloves and cardamoms.
Add all the dry spices mixed with some water. Saute till the oil separates. Now add 2 cups of water and bring it to a boil.
Gently drop in the fried fish, fried radish and green chilies. Cover and simmer till the gravy thickens. Add the tamarind paste mixed with 1/2 cup water.