01 - Preheat oven to 400°F. Line a baking sheet with parchment paper and set aside.
02 - In a mixing bowl, gently toss the peeled, cored, and sliced pears with granulated sugar, lemon juice, and ground cinnamon until evenly coated. Set aside to macerate.
03 - On a lightly floured surface, roll out the thawed puff pastry sheet to smooth any seams. Cut into 6 even rectangles.
04 - Arrange several pear slices in the center of each pastry rectangle, leaving a 1/2-inch border around the edges.
05 - Fold the edges of each pastry rectangle slightly over the pear filling to form a rustic rim.
06 - Brush the exposed pastry edges generously with beaten egg to ensure a glossy, golden finish after baking.
07 - Transfer assembled pastries to the prepared baking sheet. Bake for 20 to 25 minutes until the pastry is puffed and golden and the pears are tender.
08 - While pastries bake, warm the apricot jam and water in a small saucepan over low heat until melted and liquid. Strain through a fine mesh sieve if desired for a smoother glaze.
09 - Remove pastries from the oven and, while still warm, brush the pear filling with the prepared apricot glaze. Allow to cool slightly before serving warm or at room temperature.