Pull the chilled and cubed butter out of the refrigerator.
Quickly toss the butter in the dry ingredients.
Pour the dry ingredients and butter onto a clean countertop or marble pastry board.
Using your cold rolling pin, start to roll the butter into the dry dough.
Keep rolling and folding more flour over the butter until all the butter is pressed into long, very thin sheets. It will look very crumbly and not well incorporated – this is how you want it.
Gather the dough up, place it back in the mixing bowl, and refrigerate for 30 minutes further – this helps keep the butter firm.
Take the dough from the refrigerator and create a small cater in the center. Crack the cold egg into the middle of the dough.
Quickly mix the egg into the dough until it’s incorporated, but still shaggy. Place it (plus your rolling pin) back in the refrigerator to chill for an additional 30 minutes.
To roll the dough out, dust a sheet of wax paper with a generous amount of arrowroot flour. Place the dough in the center.
Using the palm of your hand, press the dough into a 2” thick disk and then dust with more flour.
Cover it with an additional sheet of wax paper and then, using your cold rolling pin, roll the dough out into a ¼-inch thick sheet.
If the dough cracks as you roll it out, just pinch the tear together.
And then press down to flatten the mend.
Try to roll it out into a rough circular shape.
To lay the dough in a pie pan, slide a baking sheet under the bottom sheets of wax paper so that the dough is sitting on top.
Having buttered the inside of your pie pan, lay it face-down centered on the dough.
Flip the baking sheet and pie pan over so that the pie pan is right-side up. Pull the baking sheet and wax paper away (slowly) and then guide the dough down into the pan.
Mend any breaks with additional dough and trim the edges to your liking.