Preheat oven to 400°. Lightly spray a large rimmed baking sheet with cooking spray.
Spread potatoes, fennel, and onion in a single layer on prepared pan. Drizzle with olive oil, and sprinkle evenly with Lemon- Herb Salt, rosemary, and pepper.
Bake until potatoes are browned and tender, 25 to 30 minutes. Serve immediately.
Recipe by Victoria at https://victoriamag.com/oven-roasted-greek-snapper-recipe/