Piroshki Dough without Yeast

• 2 cups (225 g) sifted all-purpose flour
• 1 teaspoon kosher salt

In a medium bowl, combine the flour and salt. Add the butter and rub into the flour until the mixture resembles coarse meal. Stir in the sour cream.

Beat the egg yolk and water together. Stir into the flour mixture to form a dough. Wrap the dough in plastic wrap and refrigerate for at least 1 hour.