Sprinkle pepper on both sides of filets, and place in a 13 x 9-inch baking dish. Combine vinegar and next 6 ingredients (lemon juice through garlic); stir well. Pour vinegar mixture over filets; cover and refrigerator 1 hour. Prepare grill. Remove filets from dish, reserving marinade. Place filets on grill rack and grill 5 minutes on each side, basting frequently with half of marinade. Combine remaining marinade with cornstarch in a small sucepan, bring to a boil and cook 1 minute or until thickened, stirring constantly.
MARINATED VEGETABLES
Combine ingredients in a large heavy-duty zip top plasic bag; seal and marinate 30 minutes, turning bag occasionally. Remove vegetables, reserving marinade. Place vegetables in a wire grilling basket coated with nonfat cooking spray. Prepare grill and place bashet on grill and grill 7 1/2 minutes on each side or until tender. Place warm marinade over grilled vegetables and serve with seabass and sauce.