1 cup almond flour
1/2 cup coconut flour
1/2 cup tapioca flour, plus more for rolling out dough
1/2 teaspoon finely ground sea salt
1/2 cup lard (very cold)
1 egg white plus 1 teaspoon water to make egg wash
1.Weigh and sift together the almond flour, coconut flour, tapioca flour and salt until combined.
2.Using a food processor or pastry cutter, cut the cold butter, palm shortening or lard into the flour mixture until the size of small peas.
3.Add the egg and pulse just until a dough begins to form.
4.Form the dough into a ball, flatten into a disk, cover with plastic wrap and refrigerate for 20 minutes.
5.Transfer the dough to a work surface covered with parchment paper that has been lightly floured with tapioca.
6.Pat the dough into a ball and flatten it into a disk.
7.Lightly dust the top of the disk with tapioca flour and use another sheet of parchment paper to cover the dough as you roll it out into a round at least 12 inches in diameter and about 1/8 inch thick. Continue sprinkling tapioca to ensure the dough doesn’t stick to the paper.
8.Carefully transfer the rolled-out dough to your chosen pan, using your fingers to repair any cracks.
9.Make an egg wash by whisking the egg white with a teaspoon of water.
10.Brush the edges of dough with the egg wash. You can also use the egg wash to help adhere any decorative cutouts to the edges of the pie dough.
11.To partially or completely bake unfilled pastry, preheat the oven to 375 to 400°F.
12.Bake for 15 to 18 minutes (10 to 12 minutes for partially baked shell).
13.Let cool completely on a wire rack before filling.