Heat oven to 200C/180C fan/gas 6.
Place a baking sheet in the oven. Lightly
flour a work surface and roll the pastry
out to a 25 x 30cm rectangle. Mix the
apples with the dates, 1 tbsp flour, the
sugar, cinnamon, lemon juice and a pinch
of salt. Spoon over one half of the pastry,
leaving a border around the edge. Brush
the edges of the pastry with a little of the
egg, then fold the other half over the top,
pressing the edges together to seal well.
Slash the top with a knife and brush with
the remaining egg.