In a large mixing bowl, add your gluten free flour, sugar, and salt. Whisk to blend them together.
Add the cold butter chunks to the dry ingredients. Use a pastry cutter to cut the butter into the flour mixture. You want the final mixture to resemble crumbs.
In a small bowl, combine the eggs, lemon juice, and water. Whisk to blend. Pour the wet ingredients into the dry ingredients and mix into a nice ball of pie crust dough.
I do not recommend using a food processor as they tend to over cut the butter and you will not get the yummy flaky layers.
Set the oven rack to the middle position and preheat the oven to 400º F.
Dust flour on the counter or a silicone mat. Place the dough ball on the mat. Cut it in half so you have a top and bottom crust.
Roll the crust to ¼-inch thickness. Place the bottom crust into a greased pie pan. Trim any extra dough around the edge, but allow a little room so you can pinch the edges into the top crust to seal the pie.
Pour the cooled pie filling into the crust.
Repeat the rolling process with the top pie crust. Carefully place the top crust over the pie filling. Use your fingers to pinch the top and bottom crust together.
If you want to make a fancier top pie crust, see the notes to learn how to make a lattice crust.
Brush the egg wash over the top of the pie crust.
Bake the pie for 20 minutes, then turn down the oven temperature to 350º F. The remaining bake time will vary by how large and deep your pie pan is. Plan to bake at 350º F for an additional 10-20 minutes.
If you notice the crust edges getting cooked too quickly, place foil over the top or around the edges so they don't overcook.
Remove the pie from the oven and allow it to cool.