Pre-heat the oven to 180°c.
To make the bechamel, heat the chicken stock and milk with the onion and bay leaf.
Melt the butter in a saucepan then whisk in the flour.
Slowly whisk in the hot liquid over medium heat until the sauce is thick and smooth.
Season with the nutmeg, salt and pepper and set aside.
To make the filling combine all the filling ingredients with the bechamel. Season to taste.
Fill pie dishes of your choice with the filling.
Cut circles out of the pastry to fit the dishes.
Brush the edges of the pie dishes with beaten egg then top with the pastry and crimp the edges. Cut a small hole in the middle of each pie to allow the steam to escape then brush each pie with some of the beaten egg.
Place in the oven and allow to bake for 20-25 minutes until the pastry is golden brown and crisp.
When cooked, remove from the oven and allow to cool for 10 minutes then serve.