Make pastry dough: In workbowl of a food processor combine flour, sugar and salt. Add butter and shortening and pulse until mixture resembles coarse meal. With motor running, pour in egg mixture and process just until dough begins to come together. Turn out dough onto plastic wrap and shape into a disk. Cover and chill for at least 1 hour.
Preheat oven to 350 degrees F. Roll out dough on a lightly floured surface and fit it into a 9-inch ceramic or glass baking dish 1 1/2 inches deep. Prick dough with a fork, line with waxed paper and weight with beans. Blind bake pastry shell for 10 minutes. Carefully remove beans and waxed paper and continue to bake 5 minutes more.
In a blender combine batter ingredients and blend until smooth. In a saute pan melt butter, add peaches and sugar and cook for 5 minutes until peaches are tender. To assemble, pour some batter into cooled shell, top with peaches, distributing them evenly, then pour remaining batter over. Bake at 350 degrees F for 1 hour, until center is just firm. Serve warm.
Recipe courtesy of David Rosengarten