Pre-heat your oven to 220C/200C Fan/425F/Gas Mark 7, grease a muffin tin with butter and strips of baking paper
To make the pastry, in a large bowl rub together the plain flour and butter with your fingers until it looks like breadcrumbs
Add the eggs and form it into a dough, be careful not to knead it or over work it, then wrap it in cling film and put it in the fridge to chill for 1 hour
To make the filling heated up the vegetable oil in a pan on a low-medium heat, fry the leeks until soft
Add the Quorn chicken pieces, and let them cook for a 2-3 minutes
Pour in the double cream, dried thyme, dried rosemary and salt, mix it together and let it cook for 5 minutes
Take the mixture off the heat, transfer it to a bowl and let it cool down fully
Roll the pastry out onto a floured surface to a thickness of around 3mm, and cut out the pie bases using a 10cm round cutter. Cut out 12 to start with, then more if you have any remaining pastry after cutting out the lids
Re-rolled the dough out and cut out the pid lids using a 7.5cm round cutter. Use a round fondant plunger, or a round piping nozzle, or a knife to cut out little circles in the middle
Place the pastry bases into the muffin tray, use your fingers to press them against the bottom and sides
Fill one with the filling, then brush the beaten egg around the edge and stick the lids on, pressing them around the sides to seal the edges. Brush more beaten egg over the tops
Bake them for 20-25 minutes until they are golden and bubbling. Remove them from the tray and either serve immediately or let them cool and serve them cold (refridgerate once cool)