The packets can be prepped up to 24 hours ahead, refrigerated, and then baked for a no-fuss dinner on busy evenings. Be sure to enjoy the delicious cooking broth over rice or noodles, or serve bread to soak up the juices.
1. Preheat oven to 400°.
2. Cut 4 (12-inch) squares of parchment paper or heavy-duty foil; spread squares out on work surface.
3. Combine oregano, 1 tablespoon oil, and next 4 ingredients in a small bowl; rub evenly over all sides of fish. Place 1 piece of fish in center of each parchment square; top each piece of fish with 2 lemon slices and 3 tomato wedges. Drizzle remaining 1 tablespoon oil evenly over fish fillets; seal the packets closed so they are airtight. Place packets on a jelly-roll pan or in a baking pan with sides.
4. Bake at 400° for 25 minutes or until fish flakes easily when tested with a fork (remove 1 packet and check for doneness before removing the others from the oven). Place packets on individual plates; cut open top of each packet with a knife. Serve immediately.
Al cartoccio (ahl kahr-TOH-chee-oh) literally means "in a bag," and these neat little packets are a handy, delicious way to cook fish.