Wash fish with tap water. Use room temperature or cold water, but not hot water.
Apply generous amount of wheat flour and keep aside for 10-15 minutes. This helps to eliminate the fish odour.
Wash the wheat flour from the fish thoroughly with running water.
Grind cumin and coriander seeds coarsely and add to a bowl. Do not make a fine powder.
Grind green chili, mint and fresh coriander to a paste and add to the same bowl.
Now add ginger paste, garlic paste, lemon juice, salt, chili powder, chili flakes and turmeric powder.
Lastly add gram flour and mix.
Apply to the fish pieces.
Cover and refrigerate over-night or at least 2 hours.
Next day, prepare the second marinade. For that, in a separate bowl add gram flour, food color, fenugreek, carom seeds and coriander seeds. Add a little water to make a smooth paste.
Add the marinade to the fish just before frying otherwise keeping it for longer will make the fish meat turn yellow.
Heat oil in a wok. Fry the fish for at least 7-8 minutes on a medium flame or until well done.