01 - Combine shredded chicken, buffalo sauce, cream cheese, and cheddar cheese in a large mixing bowl. Mix until the ingredients are evenly incorporated.
02 - On a lightly floured surface, roll out thawed puff pastry sheet to a 12 x 12-inch square. Cut into 16 equal squares.
03 - Place a spoonful of filling in the center of each puff pastry square.
04 - Fold each square into a triangle and crimp edges with a fork to seal. Arrange on a parchment-lined baking tray. Brush the tops with beaten egg.
05 - Transfer tray to a preheated 400°F (205°C) oven and bake for 18–22 minutes until pastry is golden and fully puffed.
06 - Sprinkle baked bites with sliced green onions and allow to cool slightly before serving.