I know that some people do not use xanthan gum in their pie crust. I have tried both with and without xanthan gum and I prefer crust with xanthan gum.
Whisk flour, xanthan gum, and salt.
Cut in shortening with a pastry cutter,
Beat egg in a measuring cup and then fill with milk until it totals 2/3 cup.
Mix everything together with a fork until combined.
Make into 3 balls and freeze balls that are not used.
Roll out crust between two pieces of wax paper. This helps when it is time to put the crust into the pie plate. Put into pie plate and push crust into corners.