Here is a way to use it up as a bit of a treat.
On a clean bench lay down a cup of caster sugar, spreading to about the size of your pastry sheet, and if you want to get fancy you can mix in a half teaspoon of cinnamon with the sugar. Lay your sheet of pastry down and sprinkle over enough sugar to have a thin layer covering the whole sheet of pastry.
With your rolling pin just roll it once up and down to slightly stretch it and then the same thing too the other sides, this is mostly to squish the sugar into the pastry to make it stick.
Fold the sides of the pastry in so they meet in the middle.
Fold in half.
Bake in pre heated oven 220C for approx. 15 to 20 minutes or until golden not burned, remember the sugar will melt and caramelize. Remove from the oven and allow to cool a bit.