Preheat grill to 425°F / 220°C.
Remove fish from refrigerator and allow to come to room temp for 10 minutes while grill is heating.
Slice half of the lime into wheels, reserving the other half.
Squeeze lime juice from remaining half over the fillets, then season fish with salt and pepper (or Cajun blend, if using). Place lime wheels on top of fish.
Using tongs, quickly place banana leaves on the grill and then place corvina fillets on top of leaves.
Cook for 8 - 10 minutes, maintaining the temp on the grill. If it gets too hot, do not open the lid - simply turn down the flame or crack the lid, if necessary.
Remove corvina from the grill and set aside to rest for 5 minutes before serving. Discard banana leaves.