Free-Form Apple Pie

Ingredients: (serves 6)
Gluten-free plain flour, for dusting
1 egg, separated
1/4 cup ground almonds (almond meal)
1 pound Granny Smith or Golden Delicious apples, peeled, cored, thinly sliced
2 tablespoons caster sugar
1 tablespoon demerara sugar

Pastry:
1/3 cup pure icing sugar, sifted
1 1/2 cups gluten-free plain flour
1/2 cup butter, cubed, chilled
2 to 3 tablespoons chilled water

Directions:

Make pastry Place icing sugar, flour and butter into a food processor. Process until combined. Add 2 tablespoons of water. Process until pastry just starts to come together, adding more water if necessary.
Turn pastry onto a lightly floured surface. Flatten into a disc. Wrap in baking paper. Refrigerate for 15 minutes.
Preheat oven to 375 F. Dust a large sheet of baking paper with flour. Place pastry onto baking paper. Roll out to a 12 inch circle. Transfer pastry (still on baking paper) to a large baking tray. Whisk egg yolk. Brush pastry with egg yolk, leaving a 1 inch border around edges. Sprinkle almonds over egg yolk. Arrange apple slices over pastry (leaving border free). Sprinkle with caster sugar.
Fold pastry border in over apples. Lightly whisk eggwhite. Brush pastry edges with eggwhite. Sprinkle with demerara sugar.
Bake for 15 minutes. Reduce oven temperature to 350 F. Bake for a further 15 minutes or until pastry is golden. Serve.