Get a 9-inch pie dish and apply butter to the inside to prevent the dough from sticking and set to one side.
Get one of your pre-chilled blocks of pasty from the fridge and place it on to a floured worktop and roll it out so it is about 5 cm wider than your pie dish.
Gently transfer the rolled pie base on to the pie dish and carefully push the dough into all of the corners so the dough is in contact with all parts of the pie dish.
Take the cooled filling and add it to the pie. Make sure that the filling is spread nice and evenly across the base, but make sure that you do not poke any holes in the base.
Roll out the second half of the pastry block so it is big enough to cover the pie with a 2-3 cm overlap.
Before adding the lid to the pie, make sure to brush the edges of the pie with a beaten egg as this will ensure that the lid is sealed properly.
Gently transfer the pastry lid on to the pie and crimp the edges to form a nice seal.
Cut a hole in the middle of the pie to allow the excess steam to escape while the pie is cooking.
Brush the top of the pie with more of the egg wash and then sprinkle some caster sugar on top.
You can then proceed to bake the pie straight away, but ideally, you will allow the pie to chill in the fridge for 1 hour to allow the gluten to relax and prevent any shrinkage, this also ensures the butter is really cold to allow for a flaky rise in the oven.
Bake in a pre-heated oven (190C) and bake for 40-45 minutes. Once cooked let the pie rest for 10 minutes before eating.