Preheat oven to 350°F.

Butter a 9-inch tart pan or a pie dish. Set aside. Place the all-purpose flour, whole-wheat flour, sugar (if using), and salt in a food processor; pulse to combine. Add butter one piece at a time, pulsing once or twice after each, until incorporated. Add 1/4 cup oil and 1/4 cup yogurt and pulse just until the dough begins to come together (it will be crumbly). Transfer the dough to the prepared pan, scatter the crumbs evenly, then using your fingers, press firmly into the bottom and all the way up the sides to form a crust.

Cover crust with tin foil so that the foil is touching the dough, then fill with beans or rice (alternatively, you can use a pie weights.) This step is called “blind baking” and will prevent your crust from becoming soggy once the filling is added.

If preparing a pie with a baked filling: Bake the crust for 10 minutes. Remove from oven, remove the foil and beans/rice or pie weights, prick all over with a fork, then return to oven uncovered and bake an additional 5 minutes, until lightly brown. Let cool on a wire rack. Once cool, add your filling, then bake pie as directed.

If preparing a pie with a chilled filling: Follow Step 4 as above, but when you return the crust to the oven, bake for 7-10 additional minutes (instead of 5), until the crust slightly deeper golden brown. Let cool, pour in your filling, then chill pie as directed.