Score the fish on both sides and keep aside
In a bowl, mix the ginger-garlic paste, chilli powder, turmeric powder, salt and vinegar with enough water to form a smooth paste.
Apply on either side of the fish, making sure to fill in the gashes.
Cover and keep aside for at least 30 minutes. The more you keep, the better
Heat a pan on medium-low
Add 4 tablespoons (or more) oil.
Add a few curry leaves. This is to keep the fish from sticking to the pan
Place the fish
Cover and cook for 4-6 minutes or till you get the desired crunch
Flip the fish
Continue cooking till the other side is also done.
Remove from the pan and serve hot.