1. Preheat oven to 450°F.
2. In a large bowl mix okra, corn, onion, 1 Tbsp oil & 1 tsp seasoning. Lightly coat a large glass baking dish with cooking spray. Spread vegetables evenly in dish & roast 10 minutes.
3. Meanwhile, add remaining oil & seasoning to the bowl. Whisk together. Add fish & marinate in oil mixture.
4. Remove dish from oven & stir vegetables. Place fish over vegetables & cover with foil. Bake another 10-15 minutes or unitl fish flakes easily with a fork.
5. Serve fish over vegetables.