1 Cut butter into cubes and let sit for a couple minutes: Cut the butter into cubes and put in a warm spot to take the chill off (don’t soften the butter, just let it sit out for couple minutes when you take it out of the fridge).
2 Whisk together flour, salt, sugar: In a large bowl, vigorously whisk together the flour, salt (omit if using salted butter), and sugar (if using).
3 Work the butter into the flour with your hands: Sprinkled the cubes of butter over the flour. Use your clean hands to squish the flour and butter together with your thumbs and fingers. Work the butter into the dough until you have what resembles a coarse meal with some chunks of butter.
4 Add sour cream: Add the sour cream to the flour butter mixture. Use a fork to incorporate into the mixture.
5 Form dough into disks, refrigerate: Use your hands to gather the pastry dough together into a large ball. Use a knife to cut the ball in half. Form into two disks.
Sprinkle all over with a little flour. Wrap tightly with plastic wrap and chill in the refrigerator for an hour or up to a day ahead.
If you want to freeze for future use, wrap again, this time with aluminum foil and freeze (leave in refrigerator overnight to thaw before using).
6 Remove dough from fridge, let sit for a few minutes, then roll out: After the dough has been sitting in the fridge for an hour, remove it and let it sit for 5-10 minutes at room temperature to become more malleable before rolling out.
If it still feels too stiff to roll out, hold your hands around the edges to soften.
To roll out, sprinkle a clean, flat surface with flour. As you roll the dough, check to make sure the bottom is not sticking. If it is, lift it up and sprinkle a little flour underneath.
Roll out to 12 to 14 inches wide, to an even thickness.
You can use this pastry dough for unstructured rustic pies or galettes, or single or double crusted traditional pies. It can also be used for a savory pot pie.
Whether you use the dough for a galette or a double crust pie, it will be prettier with a light egg wash. Just whisk one egg in a small bowl, add a teaspoon of water, and brush lightly over the exposed crust with a pastry brush, right before baking.
Do not use this recipe if you need to pre-bake the pie crust. The the amount of sour cream and butter that make this crust so wonderfully delicious and flakey will cause the sides of the crust to collapse if you bake it without a filling.