Preheat oven to 450°. Heat 2 teaspoons oil in a large nonstick skillet over medium heat. Add onion and the next 6 ingredients (onion through pepper). Cover and cook 10 minutes or until onion is wilted, stirring occasionally. Set aside; keep warm.Place fillets in a shallow baking dish coated with cooking spray. Brush fillets with 1/2 teaspoon oil; sprinkle with breadcrumbs and 1/8 teaspoon salt. Bake at 450° for 12 minutes or until fish flakes easily when tested with a fork. Serve the onion mixture with fish.