Preheat the oven
to 210°C/425°F/Gas mark 7. Lightly grease a
baking tray.
Roll the pastry on a lightly
floured surface to 45 x 35cm/18 x 14in. Cut out
12 rounds measuring 10cm/4in.
For the apple
filling, mix together the apple, sugar, raisins
and walnuts in a mixing bowl. Divide the filling
among the pastry rounds, then brush the edges
with water.
Fold in half and pinch firmly
together to seal. Brush the tops with egg white
and
dust with caster sugar. Make 2 small slits in
the top of each turnover.
Bake for 15 minutes,
then lower the heat to 190°C/375°F/Gas mark 5
and bake for a further 10 minutes. Serve warm.