Begin by making the pastry as described in shortcrust pastry, see below.
Then leave it to rest in a polythene bag in the refrigerator for 30 minutes.
Meanwhile, prepare the apples and all the other filling ingredients and mix them together in a bowl.
After that, pre-heat the oven to 200 C, gas mark 6.
Then roll the pastry out as described in shortcrust pastry to about 35cm in diameter, but don't worry about ragged edges - they're fine.
Now carefully roll the pastry round the rolling pin and transfer it to the centre of the baking sheet.
To prevent the pastry getting soggy from the juice of the apples, paint it with egg yolk over roughly a 25cm inner circle - this forms a kind of waterproof coating, and sprinkle over the semolina.
Now simply pile the prepared fruit mixture in the centre of the pastry, then turn in the edges of the pastry. If any breaks, just patch it back again - it's meant to look ragged and interesting.
Brush the pastry surface all round with some of the egg white, then sprinkle with the demerara sugar.
Pop the pie on the highest shelf of the oven and bake for approximately 35 minutes, or until the crust turns golden-brown.
Remove from the oven, leave to stand for 15 minutes and serve warm with whatever you like best, chilled pouring cream, ice cream, proper custard see below or click here, or crème fraiche to name a few.