1. Mix all ingredients (except banana leaves and skewers) in a bowl and marinade overnight.
2. Prepare banana leaves by quickly heating each side in a grill or pan to soften. You can also pour boiling water on it to soften.
3. Divide fish into 4 and place each portion at center of banana leaves. Fold as in a pouch and secure with toothpick or skewers.
4. Steam/Grill on a hot grill for 20 minutes. Serve with hot rice.