Preheat oven to 400°F (200°C).

1. On a lightly floured surface, roll out half of the pastry to fit the bottom of a 9-inch (23 cm) pie plate. Roll the remaining half into a ¼-inch (0.5 cm) thick circle for the top. Set aside.

2. In work bowl fitted with slicing blade and with the motor running, slice apples. Transfer to a bowl filled with enough water to cover apple slices and lemon juice. Set aside.

3. In a large bowl, blend together sugar, flour, cinnamon and nutmeg until fully incorporated. Drain apples and add to sugar mixture. Toss to fully coat apple slices. Fill bottom crust with apple mixture. Drizzle butter over top. Place top pastry crust over filling. Seal and crimp edges, trimming off any excess dough. Using a knife, make several slits in the top of the dough, or use a small cookie cutter to cut a design from the center of the pie for steam to escape. Brush top with water and sprinkle with coarse sugar. Bake in preheated oven until light brown and sugar has caramelized slightly, 40 to 55 minutes. Let cool for 1 hour before cutting.