Preheat oven to 425 degrees
Whisk together egg and 1 tablespoon water in a small bowl.
Roll 2 puff pastry sheets slightly into a square shape. Cut each sheet into 4 squares.
Place a spoonful of Boursin cheese the center of each pastry square. Top with some pieces of chicken then and some mushroom slices. Sprinkle with fresh herbs on top of the mushrooms.
Brush edges of pastry squares with egg mixture. Fold corners of each piece of puff pastry over filling in the center to make a packet, pinching to seal. Place on a large, parchment paper lined baking sheet. Brush all over the outside of them with remaining egg mixture and sprinkle with flaky salt.
Bake 10 minutes or until pastry is puffed and golden brown. Let stand 5 minutes.
YUM!
