In a large bowl combine the artichokes, tomatoes, lemon, olives, and herbs. Drizzle with olive oil, season with salt and pepper, and toss together. Take an 18-inch piece of aluminum foil and fold it in half crosswise. Fold a 1-inch strip on each side over twice, once to close and once to seal; you should now have a pouch. Repeat for 3 more pouches. Season the fillets with salt and pepper and place 1 into each pouch. Add 1/4 of the artichoke mixture to each pouch. Fold over a 1-inch strip of the top twice to seal. Place the packets onto a sheet pan and bake for 20 to 25 minutes, depending on the thickness of your fish. Carefully open the pouches and place the fish and vegetables onto warm plates. Spoon any juices that have accumulated over the fish. Serve immediately.