Pork and apple pie

Preheat the oven to 200 ºC (400 ºF). Melt the butter in a large pan and fry the pork fillet until brown. Add the cake flour and mix. Add the apple vinegar and stock, reduce the heat and simmer until the sauce thickens. Season to taste with salt and pepper. Add the apples and rosemary and mix.
On a lightly floured surface roll out the puff pastry until thinner. Line a 1,2 litre oven dish with half the pastry. Brush the pastry edge with egg yolk and cut out a lid from the remaining pastry. The lid must be large enough to cover the dish. Spoon the filling into the lined dish and cover with the pastry lid. Press the edges firmly together. Cut a cross in the centre of the pastry and fold the corners back. Brush with egg yolk and bake for 30 minutes or until the pastry is cooked and golden brown. Serve hot.
Serves 4-6