COMBINE sugar, flour and salt in medium, heavy-duty saucepan; gradually stir in evaporated milk, orange juice and egg. Cook over medium heat, stirring constantly, until dressing just comes to a boil and begins to thicken. Remove from heat. Cover; refrigerate until cool.
COMBINE chicken, celery, nuts, dressing and green onion in large bowl. Gently stir in oranges. Cover; refrigerate for 2 hours. Serve over lettuce.
* NOTE: For a lower-fat version of this recipe, substitute NESTLÉ CARNATION Evaporated Fat Free Milk for Evaporated Milk.