In a medium bowl, use a sturdy spoon to blend the cream cheese with 1 tablespoon butter until smooth. Stir in the chicken, milk, onions, salt and pepper.
On a work surface, separate the croissant dough into 4 rectangles- press the perforations to eliminate the seams. Spoon ½ cup of the chicken mixture onto the center of each rectangle. Pull the 4 corners of the dough to the top. Twist and seal to form a round ball.
Brush melted butter over each ball and then roll in breadcrumbs. Bake on an un-greased baking sheet for 20 to 25 minutes.