In a large bowl, combine the sugar, tapioca, salt, cinnamon, and nutmeg. Stir in the peaches with lemon juice. Set aside while you prepare the crust.
On a gluten-free floured surface, roll out the pastry for the bottom pie crust to approximately 11-inches in diameter. Place it in a 9-inch pie plate and trim it even with the edges.
Roll out the top crust, making it larger than the pie plate.
Pour the peach filling mixture into the bottom crust.
Dot with butter, if using.
Cover with top crust. Trim it to about ½" (1 cm) beyond the edges. Gently fold the excess edges in between the bottom crust and plate. Pinch the edges together to form a nice pattern all the way around.
Cover the edge with a foil collar to prevent over-browning.
Bake for 25 minutes. Remove foil. Bake another 20 to 25 minutes until crust is golden brown, peaches are tender, and juices are bubbly.
Serve warm.
Video
Notes
This pie is excellent served warm. However, leftovers are also good at room temperature or cold. I don't recommend reheating the pie.