Cut your peaches into 8 slices each and place in a large mixing bowl. Sprinkle the lemon juice over the top.
In your medium mixing bowl, combine flour, sugar, cinnamon, and nutmeg. Pour over peaches and mix until peaches are more or less evenly coated in the flour/sugar mixture.
If needed, roll out pie crust and place into pie plate.
Optional: beat together milk and egg white and brush over the interior of the pie crust; this can help keep the crust crisp under the fruit.
Dump the peaches into the pie crust. dot with the small pieces of chilled butter. If making a rustic crust, fold the edges of the pie crust over the top of the peaches.
Bake for 50 minutes. The crust should be golden brown and the peaches will be bubbling in juice.
Let cool for a few minutes before topping with vanilla ice cream or eating straight up.