Cheesy Leek and Potato Pie

OK so this is a but of a cheat recipe in that it's the same as the pasties but sufficiently different to warrant its own entry. IMHO.

For one pie you need:
1/2 quantity onion, leek and potato filling from the pasty recipe
1 pack ready rolled puff pastry

Line a pie dish with the puff pastry, saving the trimmings for the top. Add the filling and brush the edges with egg wash to seal. Lay on the top piece and crimp. Brush with egg wash and then bake for about 45 mins till hot and golden brown. Serve with new potatoes, veggies and lashings of gravy. Spiffing.