Make the puff pastry as per my recipe, then leave to chill completely. Line two baking trays with baking paper.

Remove the chilled pastry from the fridge and roll out to a rectangle approx 10" x 15". (If using the Jusrol pastry, this will already be rolled to size).

Spread the marinara sauce over the top of then pastry, leaving a 1-2cm border along the two long edges. Brush one of the edges with the beaten egg.

Sprinkle the cheeses evenly over the top of the sauce. Then, starting from the egg-free longest edge, roll the pastry up into a whirl. You don't want it too tight so it has some room to puff, but also not so loose that the fillings all fall out.

Use the beaten egg side to seal the end and then pop on one of the baking trays and chill for 10 minutes in the freezer or 30 minutes in the fridge. Meanwhile, preheat the oven to 200C / 180C Fan / Gas Mark 6.

When the pastry has chilled, remove from the freezer and cut into 16, even size pieces. Lay them out on a baking sheet and brush the tops with the beaten egg. If it is a hot day, place back in the freezer for 5-10 minutes to chill before baking.

Place the trays in the oven and bake for 20-25 mins until cheese is bubbling and golden. If they start to brown too much, cover with foil after around 10 minutes. Remove from the oven and leave to cool slightly before serving hot, or cool completely and serve cold in lunchboxes.