- With the rack in the middle position, preheat the oven to 350°F (180°C).
- Place the fish pieces in a 13 x 9-inch (33 x 23 cm) baking dish. Cover with the butter, capers and lemon zest. Season with salt and pepper. Cover the dish with foil. Bake for 20 minutes.
- Meanwhile, in a bowl, combine the remaining ingredients. Season with salt and pepper.
- Serve the fish and salad on plates. Drizzle the cooking juices over the fish.