First, make the dough for the pie. In a large bowl, place the gluten free flour, baking powder and salt then use a spoon to combine well. Add the chopped butter and toss to coat it in the dry ingredients. Now flatten each chunk of butter between your thumb and forefinger, you basically want to end up with flakes and once you have squished a chunk into a flake mix it with the flour in the bowl. Once all the big chunks are gone and you have a mix of flakes and flour, add 169 ml of water and mix until the dough begins to come together. Add the remaining water little by little until no part of the dough is crumbly. Turn out the dough onto a lightly floured kitchen surface and form into a circle. Sprinkle the dough lightly with some gluten free flour and roll it out into a rectangle that is about 1 inch thick. Fold the dough in half over on itself then sprinkle again lightly with flour and roll out the dough once again into a rectangle about 1 inch thick. Repeat this process three more times. Divide the dough into two equal parts, wrap each separately in cling film and place in the fridge to chill for at least 30 minutes.

Preheat your oven to 180 degrees Celcius. Now in a large bowl, place the sliced apples, sugar, salt, arrowroot powder and ground cinnamon and mix to coat the apples evenly, then set aside. Grease a metal tart tin generously and set aside. Remove one half of dough from the fridge and place on a lightly floured kitchen surface, dust lightly with flour and roll into a circle, about a third of an-inch thick. Roll the prepared dough loosely onto the rolling pin and then unroll it over the prepared tart tin. Press the pie dough gently into the bottom and up the sides of the tin then trim the excess so that the dough is covering the tin. Now arrange the apple filling on the bottom of the dough in the tin in concentric circles, overlapping one apple slice slightly over the previous one until the apples are used up and the bottom of the dough is covered.

Remove the other half of the dough from the fridge and place on a lightly floured kitchen surface, dust lightly with flour and roll it into a rough circle about one third of an inch thick. Use the rolling pin to move the circle over the tin and lay on top. Now seal the two dough pieces against each other by crimping the edge all the way around, then use a knife to cut slits into the top of the dough to allow the cooking steam to escape. Brush the top of the pie and edges generously with the egg mix and then place in the pre-heated oven and cook for approximately 40 - 45 minutes, until the top of the pie is a nice brown colour (unlike mine in the picture, although this still did the business). Allow to cool for 15 minutes.