Rinse the Chilean sea bass with cold water and pat dry with paper towels.
Set the fish in a shallow dish.
Stir together the remaining ingredients in a small bowl until well combined, then pour over the fish, turning the fish so that it is evenly coated.
Cover and marinate in the refrigerator for 1 to 3 hours.
Preheat a charcoal grill or the broiler.
Grill or broil the fish about 4 inches from the heat until well browned on one side, 3 to 5 minutes; brush with more marinade and cook on the other side until the fish is no longer opaque in the center, about 5 minutes longer.
Note: If cooking the Chilean sea bass on a charcoal grill, be sure that the fillet pieces are at least 1 1/2 inches thick to ensure that the fish won't fall apart when it is cooked.