In a medium bowl, combine the flours and salt and cut in the shortening. Mix together until crumbly. In a measuring cup, beat the egg yolk then add enough milk to make up 2/3 cup. Beat into the flour mixture until a ball starts to form. Divide the dough in half, knead if required, and roll out half onto an edged cookie sheet.

Crush 1 cup cornflakes and sprinkle evenly over dough. Peel and core apples and thinly slice onto flakes. Sprinkle lightly with sugar and cinnamon. Roll out remaining dough and cover apples. Pierce top layer with fork. Lightly beat egg white and brush on top. Bake at 375°F (190°C) for 40 minutes.

In a small bowl mix together the icing ingredients into a smooth paste. Drizzle icing over top of the still-warm pastry.

 *You can also use other fruits or fruit pie fillings to suit your taste.