Soak banana leaves in boiling water to soften. Drain, and clean with a damp cloth. Set aside.
In a large bowl, combine remaining ingredients and marinate for 20 minutes. Divide into 4 equal portions, and place on 4 banana leaves. (more than 1 leaf will be needed for each packet, as they frequently need to be overlapped where they are torn.)
Wrap securely, and fasten with a toothpick or bamboo skewer. Place packets in a steamer, and when the water boils, steam banana parcels for 20 minutes. Put the packets on four plates. Serve with the basil, cilantro, and lime wedges.