-cracker -crumbs Melt butter in a heavy saucepan over low heat; add 3 Tablespoon. flour, stirring until smooth. Cook 1 minute, stirring constantly. Gradually add half cup milk; cook over medium heat, stirring constantly, until mixture leaves sides of pan. Stir in salt and pepper. Remove from heat; stir in mayonnaise and chicken. Cover and chill 1 hour. Shape chicken mixture into 6 balls or logs. Combine egg and 1 Tablespoon. milk, mixing well. Dredge croquettes in flour, dip in egg mixture, and roll in cracker crumbs. Deep-fry, a few at a time, in hot oil (370 degrees) for 3 to 5 minutes, or until golden brown. Drain on paper towels. Yields: 6 servings