Season chicken with salt and pepper if desired. Melt butter in skillet. Add chicken and cook until browned. Remove chicken. Cover and refrigerate 15 minute or up to 24 hours.
Thaw pastry sheet at room temperature 30 minute Mix egg and water. Preheat oven to 400*F.
Unfold pastry on lightly flourd surface. foll into 14" square and cut into 4(7") squares. Spread about 2 tablespoons of the cheese spread in center of each square. Sprinkle with 1 tablespoon parsley and top with cooled chicken. Brush edges of squares with egg mixture. Fold each corner to center on top of chicken and seal edges. Place seam side down on baking sheet. Brush with egg mixture.