Preheat oven to 350.
Blend softened cream cheese, margarine, and milk until smooth. Add chicken, salt and pepper. Mix well.
Separate rolls into 4 rectangles and seal perforations (or separate into 8 rolls for smaller portions).
Spoon chicken mixture onto center of each rectangle, pull 4 corners of dough to center of mixture, and seal (or roll up smaller ones sealing the chicken inside).
Brush tops with melted butter and sprinkle with crushed croutons (optional).
Bake on ungreased cookie sheet 20-25 minutes until golden brown.
To prep chicken by boiling it: Fill a large pot with water (enough to cover the amount of chicken you want to cook) and sprinkle liberally with onion salt and celery salt. Bring to a boil over high heat. Add chicken breasts. Once it returns to a boil, reduce heat and cover. Allow to cook for about 20 min. Remove from water. Can cut immediately or wait for chicken to cool.