In med skillet over med-high heat melt butter. Season chicken with salt and pepper to taste. Add chicken and cook until browned. Remove chicken from skillet and refrigerate 15 min or overnight.
Thaw puff pastry at room temp for 30 min. Mix egg and water and set aside. Preheat oven to 400º
Unfold pastry on lightly floured pastry surface. Roll into a 14 inch square and cut into 4 – 7” squares. Spread about 2 tablespoons of cream cheese in center of each square. Sprinkle with 1 tablespoon of parsley and top with cooled chicken. Brush edges of square with egg mixture. Fold each corner on top of chicken, enclosing chicken and seal edges. Place seam side down on a ungreased baking sheet. Brush with egg mixture.
Bake 25 min or until golden brown.