Mix grated coconut, tomato, onion, garlic, coriander seeds, red chilli powder (gives that fish curry colour) and turmeric in a mixer (add little water to ease mixing).

Pour oil in a heated vessel and add onion (This is not a fodni. So no rai, jeera)

Add few cups water to the mixture.

Once onion is little fried, Add the diluted mixture to the vessel.

Add salt and kokam (4-5 pieces)

Keep low gas and let it cook. Add coriander to taste.