In a medium saucepan, combine chopped apples, butter, brown sugar, cinnamon, nutmeg, and lemon juice. Set over medium heat and simmer for about 5-8 minutes until the apples are tender.

In a small bowl, mix cornflour with cold water to form a slurry. Stir into the saucepan and cook until thickened.

Preheat your oven to 180°C (356°F) and line a baking sheet with parchment paper.

Using a round cutter, cut out 9 rounds for the bases from the first pastry sheet and create strips for the lattice from the second sheet.

Place a tablespoon of cooled apple filling onto each pastry round and position pastry strips over the filling in a lattice design.

Trim excess pastry strips and crimp edges with a fork to seal. Brush tops with whisked egg.

Transfer pies to the baking sheet and bake for 20-25 minutes until golden brown.