Preheat your oven to 375°F (190°C).
Prepare the apples by peeling, coring, and slicing them into thin wedges.
In a large bowl, combine the apple slices, sugar, cinnamon, lemon juice, melted butter, and nutmeg (if using).
Roll out the pie crusts and cut them into circles that fit your mini pie pans.
Place the dough circles into the mini pie pans, gently pressing them into the bottom and sides.
Spoon the apple filling into each crust, filling them generously.
Cut small slits in the tops of the crusts for steam to escape.
Brush the tops with the egg wash to promote browning.
Bake in the preheated oven for 20-25 minutes, or until the crust is golden and flaky.
Let the mini pies cool for a few minutes before serving.