When buying fresh ginger, look for plump roots that are not wrinkled. Don't be tempted to substitute fresh ginger for ground ginger or vice versa. Store fresh root ginger in the fridge.
Using a sharp knife, make 2-3 diagonal slits on both sides of the fish, piercing the skin so it separates. Set aside on a tray. In a small bowl, stir together fish sauce, soy sauce, oyster sauce ...