Based on Colavita's recipe, via a Flickr post.
It sounds weird that it includes vinegar, but the final product doesn't taste of it at all.
Freeze olive oil in freezer until very firm. Mix dry ingredients in a bowl and stick in refrigerator. Mix water, egg and vinegar in a bowl or cup and also chill in refrigerator.
When oil is solid, remove everything from the freezer and refrigerator. Mix oil and flour until it forms crumbs. Work liquid ingredients in until dough sticks together. Roll out and use. Don't over-work it.
Makes enough for two pies, or for one double-crust pie. Excess pastry can be sprinkled with cinnamon sugar, rolled up and cut into morsels as a treat.