Preheat the oven to 180°C / 350°F / Gas mark 4.
Line a baking tray with greaseproof paper and set aside.
In a bowl, combine the left over sauce and 1 egg. Mix well.
Use a clean surface to roll out the thawed puff pastry.
Using a cup, cut circles from each sheet of pastry.
Place 2 tbsp of the Bolognese sauce in the centre of the circle.
Brush the edges with the beaten egg then add on another circular puff pastry disc and pressing down to make sure there are no air bubble.
Use the end of a fork to seal the edges, giving it a crimping effect.
Repeat with the other circles.
Place on the baking tray and brush the pies with some more beaten egg.
Bake for 15-20 minutes, until puffed up and golden. Allow to cool before wrapping in foil.