Preparation Position rack in top third of oven and preheat to 500°F. Spray small baking sheet with nonstick vegetable oil spray. Whisk all purpose flour, yellow cornmeal and chili powder in shallow dish to blend. Stir mayonnaise and fresh lemon juice in another shallow dish to blend. Sprinkle fish fillets on all sides with salt and pepper. Dip fish fillets into mayonnaise mixture, then into flour mixture to coat completely. Arrange fish on prepared sheet. Bake until coating is crisp and golden and fish is cooked through, about 10 minutes.
Preparation Position rack in top third of oven and preheat to 500°F. Spray small baking sheet with nonstick vegetable oil spray. Whisk all purpose flour, yellow cornmeal and chili powder in shallow dish to blend. Stir mayonnaise and fresh lemon juice in another shallow dish to blend. Sprinkle fish fillets on all sides with salt and pepper. Dip fish fillets into mayonnaise mixture, then into flour mixture to coat completely. Arrange fish on prepared sheet. Bake until coating is crisp and golden and fish is cooked through, about 10 minutes.