01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper and set aside.
02 - In a skillet over medium heat, melt the butter. Add the diced pears, brown sugar, cinnamon, nutmeg, and lemon juice. Cook for 5 to 7 minutes, stirring occasionally, until the pears are tender and the mixture has thickened. Remove from heat and let cool for 10 minutes.
03 - On a lightly floured surface, roll out the puff pastry if needed. Cut into 6 equal rectangles or squares.
04 - Place a spoonful of the pear filling onto one half of each pastry square. Fold the pastry over to enclose the filling, forming a triangle or rectangle. Press the edges firmly with a fork to seal.
05 - Transfer the assembled pastries to the prepared baking sheet. Brush the tops with beaten egg and sprinkle evenly with granulated sugar.
06 - Bake for 18 to 22 minutes, or until the pastries are golden brown and fully puffed.
07 - Allow the pastries to cool slightly before serving. Serve warm on its own or paired with a scoop of vanilla ice cream.