Preheat oven to 400 degrees and line a baking sheet with parchment paper.

Unfold the pastry sheets on a lightly floured surface. Cut each sheet into 6 squares.

Divide chocolate evenly among the 12 squares. Place chocolate chips or bars at the edge of each pastry square. Roll tightly, completely encasing the chocolate inside and place seam side down on the baking sheet.

In a bowl, beat egg and water together. Brush each pastry with egg mixture and sprinkle lightly with sugar.

Bake for 12-15 minutes until the pastries are golden brown. Let the pastries cool on the baking sheets for 10 about minutes. Serve warm or at room temperature. Makes 12 pastries.