1. In a small bowl mix the marinade ingredients. Place the fillets on a sheet pan and spoon the marinade over the fillets. Allow the fish to marinate at room temperature for about 20 minutes while you preheat the grill.
2. Prepare the grill for direct cooking over medium heat (350° to 450°F) and preheat the grill pan.
3. Using a spatula, transfer the fillets from the sheet pan directly to the grill and discard any remaining marinade left on the sheet pan. Arrange the tomatoes on the grill pan in a single layer and grill the fish and tomatoes over direct medium heat, with the lid closed as much as possible, until the fish is just opaque at the center and the tomatoes are warm and have collapsed, about 6 minutes, turning the tomatoes once or twice. Do not turn the fish. Remove from the grill and serve the fillets warm with the tomatoes.