1Move oven rack to position slightly above middle of oven. Heat oven to 500°F. Remove and discard skin from fish. Cut fish into 2x1 1/2-inch pieces.
2In small bowl, mix buttermilk and egg white with fork. In another small bowl, mix cornmeal, bread crumbs and Cajun seasoning. Dip fish into buttermilk mixture, then coat with cornmeal mixture. Place in ungreased 13x9-inch pan. Lightly spray cooking spray on fish.
3Bake about 10 minutes or until fish flakes easily with fork. Serve with lemon wedges.