Step 1

Whisk whole-wheat flour and all-purpose flour with salt in a medium bowl. Cut butter into small pieces; using your fingers, quickly rub the butter into the dry ingredients until smaller but still visible.

Step 2

Add sour cream and oil; toss with a fork to combine with the dry ingredients. Sprinkle 2 tablespoons of ice water over the mixture. Toss with a fork until evenly moist; if the mixture seems dry, add up to 1 more tablespoon water. Knead the dough in the bowl a few times--the mixture may still be a little crumbly--then firmly press into a disk. Cover the bowl with plastic wrap and refrigerate for at least 1 hour and up to 2 days. Or wrap airtight and freeze for up to 3 months.