Cut half of one pack of pastry and roll into a rectangle about a 20p coin of thickness (for non-english people this is about 2cm) and 28cmX28cm on a lightly floured surface.
Lay onto a greased baking sheet and prick well with a fork.
Bake the pastry case for about 10 or 15 mins until golden brown and and crisp. Leave to cool.
Meanwhile melt the butter (I did this in a bowl in the microwave) and add the crushed garlic then allow to cool slightly.
Then mix the butter/garlic with the cheese and bread crumbs.
Scatter half the cheese mixture onto the cooked pastry base leaving a border of at least 2.5cm.
Sprinkle over the roughly chopped ham, soured cream and chives.
Tip the remaining cheese mixture over evenly and sprinkle with the lemon juice.
Season with salt and pepper.
Roll out the rest of the pastry into a size 5cm larger than the pastry base (on all sides).
Use the beaten egg to glaze the edges of the base and then place the newly rolled pastry square over the top of the pie. Push down the edges and trim to fit then scallop the edges with a knife. Glaze the top with egg.
Bake for around 25-30 mins until golden brown and crisp then serve.