Grind small onions, kashmiri red chilly powder, turmeric powder, pepper powder, ginger , garlic and salt to a fine paste. Apply this paste to the fish on all sides evenly using your hands. Rest it for 1 -2 hours refrigerated in a closed vessel.
For marination
Clean the fish, use fork and prick all the sides of fish to make tiny holes so that the marination gets in deeper.
Pan fry
Heat oil in a wide pan, place the marinated pieces on it. cook on both sides until its toasted and turns brown. Serve hot with sliced onions