Heat a heavy skillet over medium heat. In a bowl, mix together the mayonnaise, sour cream, blue cheese, celery and green onions. Season the mixture with salt and pepper.
Slice the rolls in half and butter each slice on the outside. Spread blue cheese dressing on the inside of each roll. Pile the chicken on the bottom half of the roll and cover with the top half. Place in the hot skillet and press down with a heavy spatula or small heavy pan for about 2 minutes. Flip and press down for an additional 2 to 3 minutes. Serve and - Enjoy!