Thaw fish, if frozen. Cut into 2 serving-size pieces, if necessary. Set aside.
In a shallow dish combine egg white and water. In another shallow dish combine the cornmeal, chopped poblano pepper, bread crumbs, Parmesan cheese, and salt. Place flour in a third shallow dish. Dip each piece of fish in flour, then in egg mixture, then coat evenly with cornmeal mixture.
In a large skillet heat the oil over medium heat. Add the fish and fry for 4 to 5 minutes on each side or until golden brown and fish flakes easily with a fork.