Transfer the fish to a large mixing bowl. Now add the onions, green chillies, red chili powder, turmeric powder and salt. Keep aside, 15 odd minutes.
Add rice flour and besan, give it a hearty mix. No water to begin with. If it feels too dry, add just a splash of water, mix again. Take a small portion of the ‘dough’, press gently using your palm, see if it holds on its own. If it doesn’t add another splash of water, repeat.
Heat oil for deep frying.
Grease your palm with a little oil, take a small portion of the ‘dough’, press gently, release into the oil carefully.
Fry on a medium flame till golden and crisp. Keep aside on a kitchen absorbent towel.
Serve hot with kasundi.