2 sheets frozen puff pastry, thawed
2/3 cup strawberry jam
1 large egg yolk, lightly beaten
1 tablespoon lemon juice
1/3 cup confectioners' sugar
On a lightly floured work surface, roll out pastry sheets to 1/8 inch thick. Cut each sheet into quarters and place on a parchment-lined baking sheet. Spoon 1 heaping tablespoon jam in center of each piece, brush edges with egg yolk, fold into triangles or squares, and press tightly to seal edges. Freeze pies until firm, 30 minutes.
Preheat oven to 375 degrees. Bake pies until golden and puffed, 20 to 25 minutes. Let cool completely on sheet on wire rack. Whisk lemon juice and confectioners' sugar until smooth. Drizzle glaze over cooled pies and let set 20 minutes.