Preheat oven to 400˚F.
Line a medium baking dish with a sheet of foil big enough to make a packet, about 12 to 14 inches long. Place fish in the baking dish.
Top fish with tomatoes, olive oil, and parsley.
Fold the sides of the foil inwards around the fish, and fold in the top and bottom of the foil. Pinch the foil closed to create a package.
Bake for 18-20 minutes or until fish is flaky and opaque. When cooked, open the packet carefully to avoid spilling the juices. Serve immediately.