Preheat the oven to 200°C. Grease a large baking sheet with nonstick spray.
1. Roll the puff pastry out until it’s a little thinner. Slice a 3mm strip off each side to create a neat square or rectangle.
2. Put the pastry on the prepared baking sheet. Brush milk on the edges and stick the strips you cut off all around the edges. Press down to ensure it sticks. Cut notches in the centre of the pastry. Bake for about 20-30 minute or until the edges are puffed up and the pastry is light brown.