Sprinkle a 9-inch pie pan lightly with flour.
Combine flours and salt in a bowl.
Cut butter in with knives or a grater.
Add oil gradually, working it in with fingers, then the ice water.
Knead dough briefly until water is distributed evenly.
Press into prepared pie pan or roll out between well-floured sheets of wax paper and place in pie pan, making a high fluted edge around the outside.
If baking shell without filling, prick it well with a fork.
Bake in preheated oven for 10 to 12 minutes.