1.Heat the oven to 400°F. Beat the egg and water in a small bowl with a fork.
2.Sprinkle the flour on the work suface. Unfold the pastry sheet on the work surface. Roll the pastry sheet into a 12-inch square. Cut into 4 (6-inch) squares. Brush the edges of the pastries with the egg mixture.
3.With a corner of 1 pastry facing you, place 2 slices ham and 1 slice cheese on the bottom half of the pastry. Fold the pastry over the filling to form a triangle and press the edges to seal. Crimp the edges with a fork. Repeat with the remaining pastries. Brush the pastries with the egg mixture. Place the pastries onto a baking sheet.
4.Bake for 20 minutes or until the pastries are golden brown. Sprinkle the pastries with the confectioners' sugar. Serve with the maple syrup.
5.Easy Substitution: For a savory twist, serve with Dijon-style mustard instead of the maple syrup.
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