Creating the Puff Pastry Apple Tart is an enjoyable process that is straightforward when broken down into clear steps. Follow this guide to achieve a delicious dessert:

1. Preheat the Oven: Preheat your oven to 400°F (200°C).

2. Prepare the Puff Pastry: Roll out the thawed puff pastry sheet on a lightly floured surface to fit your tart pan. If using a baking sheet, ensure it’s large enough to accommodate the pastry.

3. Place the Pastry in the Pan: Transfer the rolled pastry to the tart pan, pressing it gently into the edges. Trim any excess pastry hanging over the edges.

4. Prepare the Apples: In a large bowl, combine the sliced apples, granulated sugar, ground cinnamon, nutmeg, lemon juice, and cornstarch. Toss well until the apples are coated evenly.

5. Arrange the Apple Mixture: Carefully pour the apple mixture into the center of the pastry, spreading it evenly.

6. Fold the Edges: Gently fold the edges of the pastry over the apples, creating a border. It doesn’t have to be perfect—this rustic touch adds to its charm.

7. Make the Egg Wash: In a small bowl, beat the egg with the milk. Brush the egg wash over the pastry edges for a golden finish.

8. Bake: Place the tart in the preheated oven and bake for 30-35 minutes or until the pastry is golden brown and the apples are tender.

9. Cool the Tart: Remove from the oven and let cool for about 10-15 minutes in the pan.

10. Dust with Powdered Sugar: For an optional touch, dust with powdered sugar before serving.

By following these simple yet effective steps, you’ll be able to create a Puff Pastry Apple Tart that is not only flavorful but also a feast for the eyes.