Position a rack in the upper third of the oven and preheat to 475 degrees F. Season the fish with salt and pepper and refrigerate until ready to use. Remove the zest from the lemon using a vegetable peeler (reserve the lemon). Combine the lemon zest, parsley, garlic, 2 tablespoons olive oil and 1 teaspoon salt in a food processor. With the motor running, gradually add the bread and pulse several times to make coarse crumbs. Spread the breadcrumbs evenly in a 9-by-13-inch baking dish. Arrange the artichokes, olives and tomatoes around the edge and bake until the exposed breadcrumbs in the middle are toasted, about 15 minutes. Remove the baking dish from the oven. Scoop out the toasted breadcrumbs and set aside. Add the fish to the baking dish and top with the toasted breadcrumbs. Bake until the fish is cooked through, about 15 minutes. Drizzle with the remaining 2 tablespoons olive oil. Cut the reserved lemon into wedges and squeeze on top.