Buttermilk Custard Pie

To make crust: Stir together 1 cup flour, 1 tablespoon sugar and 1/8 teaspoon salt in a medium bowl. Melt butter in a small saucepan over low heat. Cook, swirling the pan, until the butter turns a nutty brown, about 30 seconds. Pour into a small bowl and let cool. Stir in oil. Slowly stir the butter-oil mixture into the flour with a fork until the mixture is crumbly. Gradually stir in enough ice water so that the dough will hold together. Press the dough into a flattened disk.

Place two overlapping lengths of plastic wrap on the work surface. Set the dough in the center and cover with two more sheets of plastic wrap. With a rolling pin, roll the dough into a circle about 12 inches in diameter. Remove the top sheets and invert the dough into a 9-inch pie pan. Remove the remaining wrap. Fold the edges under at the rim and crimp. Cover loosely with plastic wrap and refrigerate for 15 minutes.

Preheat oven to 375°F. Line the pastry shell with a piece of foil or parchment paper and fill with pie weights or dried beans. Bake for 15 minutes, remove weights and foil or paper and bake until the crust is golden, 8 to 10 minutes longer. Reduce oven temperature to 350°. Cool the pie crust on a wire rack while you make the filling.

To make filling: Whisk together 3/4 cup sugar, 1/4 cup flour, cornstarch and 1/2 teaspoon salt in a mixing bowl. Whisk together eggs and egg white in another bowl until frothy. Whisk in buttermilk, lemon juice and vanilla. Gradually whisk the liquids into the dry ingredients. Pour into the crust and sprinkle the top with grated nutmeg.

Cover the edges of the crust with foil and bake until the pie is no longer wobbly in the center, 30 to 40 minutes (do not use a knife to check for doneness or a crack will result). Cool on a wire rack for 15 minutes, and then in the refrigerator until completely cool, about 2 hours. Just before serving, arrange fresh berries around the edge of the pie, if desired.