Measure almond flour, arrowroot powder, and starch into a medium bowl and whisk 'til well combined.

Slice the butter and toss the slices in the flour mixture to coat, then cut in with a pastry cutter or two butter knives until most of the largest clumps are slightly smaller than pea-sized.

Add water little by little until the dough comes together in a ball. (Only use as much as you need for this to happen.)

Form dough into a ball with your hands, and place it in the center of a piece of plastic wrap or waxed paper.

Flatten the ball of dough into a disk with your hands.

Top the dough with a second piece of plastic wrap or waxed paper, and roll out from the center to form a circle about 11 inches in diameter.

Remove the top sheet of plastic wrap/waxed paper, and flip the dough into a lightly-greased pie pan. (Chill while you prepare your pie filling.)

Bake and fill -OR- fill and bake according to the instructions in your recipe.