Clean fish slices, wipe it dry and set aside.
In a pan, dry roast black peppercorns, fennel seeds, cumin seeds, mustard seeds , ginger, garlic and curry leaves.
Pound them in a mortar and pestle or a mixer jar into a powder.
Now add the chopped tomato, turmeric powder, red chili powder, coriander powder , salt , tamarind and oil .
Blend in a mixer jar till smooth.
Apply the masala ( spice paste) all over the fish pieces.
Marinate the fish and keep in the fridge minimum 4 hours .
After 4 hours, sprinkle some cornflour or over the fish. The cornflour helps the masala to stick
In a pan, heat 2-3 tablespoon of oil and fry the fish.
Serve hot with a bit of lemon squeezed, sprinkle some fried curry leaves and green chillies over and a few lemon wedges, onion slices , on the side.