First marinate the fish with salt and half the lemon juice for 1 hour.
Grind the coconut, green chillies, green coriander, ginger garlic paste to a smooth paste. Add salt and the remaining lemon juice.
Wash the marinated fish and apply the coconut paste on both sides of the fish. Cut the banana leaves large enough to wrap each piece of fish. Spread a little oil over the leaves and wrap each piece like a parcel. Tie with a cotton thread, and steam in a large steamer for 20 minutes. It can also be baked in an oven at 180deg C for 15 minutes.
Remove the string and serve.
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