Prepare the ingredients
Transfer the Patrani marinade to a bowl. Evenly marinate each fillet and place the fillets in the refrigerator before you move to #2. Cut the lemons into wedges and set aside.
Blanch the banana leaves
Set a pot of water to boil. Flash blanch each banana leaf in the boiling water for 2-3 seconds. Pat the leaves dry with a paper towel.
Assemble the packets
Place a fillet in the middle of a banana leaf. Fold the leaves tightly over the fish from each side, ensuring that the packet is properly sealed. Repeat for all 6 fillets.
Cook the fish
Preheat the oven at 200C. On a baking tray, place the packets of fish with the folded sides facing down to prevent them from opening. Bake for 8-10 minutes or until they are just cooked.
Serve
Once cooked, carefully transfer the wrapped fish and lemon wedges to a plate and serve hot.