Fresh Peach and Rhubarb Pie

FOR THE CRUST:
In a food processor fitted with the metal blade, combine the flour and salt. Process briefly to blend. Add the butter and shortening and process until the mixture resembles coarse meal, 5-10 seconds. With the motor running, gradually add the egg yolk, lemon juice, and just enough of the ice water for the dough to come together and hold a shape when pressed. Remove the dough from the processor, divide into 2 pieces, one slightly larger than the other, and flatten into 2 thick disks. Wrap the disks in plastic wrap and refrigerate for 1-2 hours.

FOR THE FILLING:
In a large bowl, combine the rhubarb, peaches, lemon juice, sugar, nutmeg, cinnamon and flour and toss until mixed.

On a lightly floured work surface, roll out the larger of the 2 disks into a round about 11 inches in diameter. Gently ease the pastry round into a deep 9-inch pie plate and press into the plate, crimping the edges about 1/2 inch above the level of the plate rim. Brush the pie crust with the egg-water mixture. Spoon the filling into the dish.

On the lightly floured work surface, roll out the remaining disk into a round about 10 inches in diameter. Using another pie plate as a guide, cut out a 9-inch round from the dough. Cut the round into strips 1 inch wide.

Preheat an oven to 425 degrees F.

Brush the edge of the bottom crust with a little more of the egg-water mixture. Lay a row of dough strips 3/4 inch apart across the top of the pie. Press the ends firmly to the edge of the crust. Lay the remaining strips in the opposite direction, again pressing them firmly to the edge. Flute the edge decoratively. Brush the pastry edge and strips with the egg-water mixture.

Place the pie on a baking sheet and bake for 10 minutes. Reduce the heat to 350 degrees F. and continue baking until golden brown and bubbling, 35-45 minutes. (Check the pie during baking and cover the edges with aluminum foil if the crust begins to overbrown.)

TO SERVE:
Transfer to a rack and let cool for at least 20 minutes before serving. Serve warm or at room temperature.