Flaky Gluten Free Pie Pastry

Cut butter into ¼-inch pieces and freeze for 15 minutes. Meanwhile measure the wet and dry ingredients separately.
In 1-cup measuring cup combine water, sour cream and vinegar. Stir and set aside.
Combine flour, sugar, salt and xanthan gum in the bowl of a food processor. Turn on briefly to combine.
Add cold butter to processor and turn on until combined into uniform crumb-like mixture with no visible pieces of butter.
Add sour cream mixture, mix until it looks like dough and is sticking together. If it looks dry continue mixing it.
Transfer dough to large piece of wax paper. Using your hands mix in any last bits of flour.
Divide the dough ball into 2 pieces for pie, or smaller pieces as desired for other recipes.
Place each dough ball onto a piece of wax paper large enough to wrap completely. Flatten pastry into a disk and wrap. Refrigerate for 20 minutes.

Preheat oven as directed in recipe. Remove dough from fridge, unwrap and leave in the center of the wax paper. Top with a second piece of paper to decrease the amount of sprinkling flour needed.
Using a rolling pin start in the center of the dough, rolling out toward the edges. Lift the rolling pin at the edges. Avoid rolling off the edge of the dough making the edges thinner than the rest of the pastry.
Use a thin cutting board or flexible cutting mat to support pastry and flip it over. Lift the paper to see how sticky it is. Sprinkle with a small amount of flour only if needed. You want the paper to easily peel off so check both sides. Put the paper back on the dough and continue rolling until you have a large circle about ⅛-inch thick. The circle should be 1 or 2 inches larger than your pie plate.
Remove wax paper and invert the dough into the pie plate. Working quickly, gently push the edges of the dough into the sloped sides of the pie plate before the pastry cracks. Trim the edges with a knife or scissors.
To make a thick edge crust tuck the excess dough under itself, crimping the edge into the rim as you go. Alternately, push the dough into the rim of the pan with your thumb and fingers.
Chill pastry in freezer for 15 minutes before baking.
Bake according to your recipe.