Preheat oven 180°C. First, make the pastry.
Sieve the flour and the icing sugar into a bowl. Cut the butter and margarine into small cubes, and then rub into the flour until they resemble breadcrumbs
Combine together the egg and water. Mix into the dry ingredients until a dough is formed. Wrap in cling film and refrigerate for at least 20-30 minutes or until needed.
Peel and core the apples, cut into quarters. Melt butter in a large shallow heavy based pan over a low heat. Stir in the sugar then add in the apples. Cook on a medium to low heat until the apples begin to soften and the sauce goes a brown toffee colour. Remove from the heat. Stir in the cinnamon and allow to cool completely.
Grease and flour a 9" tart tin. Divide the pastry in half. Roll out both pieces and line the pie dish with one. Pour in the cooked cooled apples and toffee sauce.
To create the lattice on top, roll out the remaining piece of pastry into a long rectangle. Cut out ten long strips. Put five strips length ways across the top. Folding back every second strip half way. Take another strip of pastry and put it across the pastry strips then fold the pastry back down on top of the strip. Repeat this until all the pastry has been used to form an interweaving effect know as a lattice
Make the egg wash by mixing the egg with 1 tablespoon of cold water. Brush all the edges of the pastry first, lift up the pastry over hang and egg wash under it. Then egg wash all the remaining top. Trim of any excess pastry. Put in the fridge for 30 minutes.
Bake at 180°C for 20 minutes then reduce to 170°C for 15 to 20 minutes until the pie is a golden brown.
Recipe supplied by Louise Lennox