Saute the lardons until starting to crisp. Add the onion and cook for a further 5 minutes over a low heat.Leave to cool slightly, then crumble in the stilton and mix well together to form a thick paste. Cool.
Roll pastry into a square 30cm/12” X 25cm/10”.
Spread the paste evenly over the pastry, going right to the edges. Press down well.
Roll from the top edge towards you, keeping it as tight as you can without squashing the roll.
Tuck in the ends and ensure the join is well sealed. Score at 1cm spaces. Chill well. By chilling for a longer time you will have a better round shape as it cuts more cleanly.
When ready to cook, cut into rounds using the score marks. Place on a baking tray leaving room for spreading.
Bake for 15 minutes until golden.
Notes
Tip: Save any odd bits of leftover stilton, by crumbling them and storing in a pot in the freezer. They can be used for the recipe above or soups and sauces.