Tomatoes, olives and lemon give this dish its Mediterranean flavors. A mixture of mayonnaise and Parmesan cheese spread over the top of the fillet creates a tasty coating that also helps keep the fish moist during baking.
Preheat oven to 450 degrees. In a small ovenproof skillet or baking dish, arrange tomatoes in overlapping circles. Scatter olives and lemon zest over the tomatoes. Season with salt and pepper; drizzle with olive oil.
In a small bowl, stir together mayonnaise, Parmesan, and lemon juice. Place fish on top of tomatoes in skillet. Season fish with salt and pepper. Spread mayonnaise mixture on top.
Bake until fish is opaque throughout and topping is golden brown in spots, about 20 minutes.
To adapt this recipe for four, use 4 times the amount of each ingredient. Use a 9-by-13-inch baking dish.