Mix all the ingredients except the oil and apply to the fish. Marinate for about 1/2 an hour.
Heat the oil in a kadahi; when hot, add as many pieces as fit in comfortably. Fry over high heat till lightly coloured, and the masala forms a coat over it.
Remove fish from oil, and set aside over a colander.
Heat oil again, before frying the remaining pieces.
Before serving, heat the oil and add the pieces of fish to it; press them down a little and fry till cooked through and crisp on top.
Drain on an absorbent paper and serve hot, sprinkled with chaat masala and lemon wedges on the side.
Key Ingredients: cat fish, bell pepper, carom seeds, gram flour, garlic, mustard oil, red chilli, salt, lemon rind