In a medium mixing bowl, combine the drained canned peach slices with cornstarch, stirring gently to coat the fruit evenly. If desired, add sugar and a sprinkle of cinnamon to enhance flavor.

Lightly dust your work surface with flour and roll out the thawed puff pastry sheet until it’s smooth and nearly double in size.

Take the prepared peach filling and place a generous spoonful on one half of each pastry rectangle, then fold over and seal the edges.

Preheat your oven to 400°F (200°C) and brush the tops of the pastries with the egg wash. Bake for 18–22 minutes until golden brown.

Remove from the oven and let cool on the tray for a few minutes before serving.