Mix milk, sugar, butter and salt in a pot. Bring to a full boil, then boil for 5 minutes stirring constantly. Remove from heat. Add marshmallows, chocolate chips, flavoring and walnuts. Stir vigorously until marshmallows are melted and thoroughly blended. Pour into 8 inch square pan. Chill. Makes about 2 pounds. Origin: My Mom, Shirley Whittaker, Richmond B.C. Canada. Shared by: Sharon Stevens Oct/91