1. Mix the yoghurt with cream, garlic paste, carom seeds, white pepper, cumin powder, garam masala, salt, lemon juice, mint chutney, and gram / rice flour.
2. Add fish cubes to the marinade, coat evenly and keep aside for 2 - 3 hours.
3. Skewer fish 2 cm apart and roast in a preheated grill / tandoor / oven (180°C (350°F)) for 8 - 10 minutes. Baste with butter / oil once, before roasting is complete.
4. Garnish with onion rings and serve hot.