To prepare the bottle masala, dry roast all the spices till aromatic and fragrant. Cool and grind to a powder. Store in an airtight bottle or container and use as necessary.
Clean the fish and cut into medium slices.
To prepare the marinade, mix 2 tbsp of the bottle masala with the juice of half a lemon, salt and enough water to make a paste. This is a spicy marinade so adjust quantities according to personal preference or depending on the quantity of fish.
Apply liberally on the fish pieces and keep aside for at least 2 hours or longer if time permits.
Heat vegetable oil in a flat pan and shallow fry the fish pieces on both sides till done.
Serve hot with lemon wedges and a side of green salad.