Preheat oven to 190°C (fan bake) or 210°C (conventional). Roll 2/3 of the pastry to line a 24cm diameter pie dish. Spoon in the filling. Wet the edges of the pastry. Roll out the remaining pastry and place over the filling. Trim the pastry and crimp the edges of the pastry together. Make a small cut in the top of the pie to allow the steam to be released. Brush pastry top with the beaten egg or milk. Bake for 25-30 minutes until pastry is golden and filling hot. Serve with your favourite seasonal vegetables.