Preheat the oven according to the temperature stated on your pack of puff pastry.
Line a baking tray with baking paper and lay the puff pastry circle on top. Cut in half. Place a bowl in the centre and press to make an indentation in the pastry (this will act as a guide for slicing later).
Remove the bowl and start cutting the pastry from the edge of the indent to the outer edge of the pastry. You can make as many or as few slices as you like, but I did about 12 per half-circle.
Fill the uncut insides of the indent with 1 to 2 tablespoons of your favourite jam. Fold over the slices of pastry to form a crescent shape.
Bake in the preheated oven according to your puff pastry's instructions.