Place potatoes in the bottom of a slow cooker.
Sprinkle with ½ package of dry Italian dressing mix.
Add chicken pieces and green beans on top of potatoes.
Sprinkle with remaining Italian dressing mix.
Cube butter on top and add ¼ cup of water.
Cover and cook on LOW 6-8 hours or HIGH for 4-5 hours. Potatoes should be tender.
