Thaw fish, if frozen. Rinse the fish; pat dry with paper towels. Sprinkle the fish with pepper. Combine drained tomatoes, scallions, oil, garlic, capers, oregano, and thyme in a small bowl; set aside.Advertisement
Fold a 36x18-inch piece of heavy-duty foil in half to make an 18-inch square. Place the fish fillets in the center of the foil. Top with the tomato mixture. Bring up two opposite edges of the foil; seal with a double fold. Fold the remaining edges together to completely enclose the fish, leaving space for steam to build.
Place the foil packet on the rack of an uncovered grill directly over medium coals. Grill for 8 to 12 minutes or until the fish flakes easily when tested with a fork.