Clean and wash fish.
Make fillets and cut each fillet into two.
Make horizontal slits on the pieces. Sprinkle vinegar and salt and miarinate for 30 minutes.
Trim, wash and wipe banana leaves. Cut coconut into pieces. Clean and chop coriander.
Wash, slit and remove the seeds from the green chillies. Peel garlic.
Now put all these and the remaining ingredients in the mixie to make a smooth paste. Keep aside.
Stuff fish pieces with chutney and spread the rest on both sides. Apply oil on banana leaves and wrap each piece separately.
Steam the wrapped fish pieces for 30 minutes. Cut lemon into wedges.
After 30 minutes, remove fish from steam, unwrap arrange on a platter and serve with lemon wedges.