Heat coconut oil in a large frying pan, which will fit all the fish at one go.

Add the onions and saute till soft. You don't need to brown the onion as such, it has to just be wilted.

Then add in the ginger and garlic pastes and cook till the raw smell is gone.

Add in the powders from turmeric to pepper and saute for a couple of minutes.

Now add in the vinegar and salt and give a good mix.

Spread the fish on top of this masala, slowly mix using your wooden spoon just to quote the masalas.

Pour the coconut milk on top, keep the flame on medium low and cook closed till the fish is cooked well. It is not necessary to flip the fish, but if you are doubtful, then you may do it.

Switch off the flame, sprinkle in the curry leaves. Close back the lid and keep it undisturbed for around 15 minutes.

Open the lid, give one final mix, adjust the salt and serve!!! One of the best fish curries I have ever had in recent times...