• Place the almond flour, tapioca flour, coconut flour, and salt in a large mixing bowl or in a food processor fitted with an “S” blade. Mix or pulse to combine.
• Add the chilled butter and use a pastry blender to cut in the butter or process in your food processor until the the mixture resembles a sand-like consistency. 
• Add the egg and vinegar and mix until the dough comes together.
• Remove the dough from the bowl and form into a disc. Wrap in plastic wrap and refrigerate for 30 minutes.

Blind Bake Pie Crust

• Preheat your oven to 375 degrees F.
• Roll out your chilled pie dough to fit the size of your pie plate. Carefully transfer the dough to the pie plate and crimp the edges. Use a fork to prick holes all over the bottom of the crust. *If you are having a difficult time transferring the dough to your pie plate, simply press the crust into the pie pan. 
• Place the pie plate in the freezer for 10 minutes. Then, place a sheet of parchment paper over the pie crust and fill with pie weights, dried beans, or rice. 
• Bake the crust for 15 minutes, then remove the pie from the oven and carefully lift the parchment paper out of the pie. 
• Return the uncovered pie crust to the oven and bake for another 5 minutes. Remove from the oven and set aside while you prepare the filling.