Creating these Peach Turnovers is straightforward. Just follow these easy steps:

1. Preheat Oven: Begin by preheating your oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. Prepare Filling: In a bowl, mix the diced peaches, granulated sugar, lemon juice, ground cinnamon, and cornstarch. Stir until well combined.
3. Roll Out Pastry: On a floured surface, roll out each sheet of puff pastry. Cut each sheet into four squares.
4. Add Filling: Place a spoonful of the peach mixture in the center of each pastry square. Be careful not to overfill.
5. Fold Pastry: Fold the square diagonally to form a triangle, pressing the edges with a fork to seal tightly.
6. Make Egg Wash: In a small bowl, whisk together the egg and milk for the egg wash.
7. Brush with Egg Wash: Brush the tops of each turnover with the egg wash for a golden finish.
8. Bake: Place the turnovers on the prepared baking sheet and bake for 25-30 minutes or until golden brown.
9. Cool: Remove the turnovers from the oven, allow them to cool on a wire rack for about 10 minutes.
10. Dust with Powdered Sugar (Optional): For a touch of sweetness, dust them with powdered sugar before serving.

These steps lead you through making incredible Peach Turnovers that not only satisfy your sweet tooth but also light up your kitchen with a warm, inviting aroma.