Use peaches packed in heavy syrup for this dessert. The sweetness from the syrup tames the tartness of the cranberries in this pie.
Preheat oven to 375 degree F. Drain peach slices, reserving 1/2 cup syrup. Cut the peach slices crosswise into thirds; set aside. In a large saucepan, combine reserved syrup and cranberries. Bring to boiling; reduce heat to medium. Cook, uncovered, until the cranberry skins pop, stirring occasionally (about 2 minutes).
In a small bowl, stir together sugar and cornstarch. Add sugar mixture to the cranberry mixture. Cook and stir until thickened and bubbly. Remove from heat; stir in the peaches. Set aside and keep warm.
In a medium bowl, stir together flour and salt. Using a pastry blender, cut in shortening until pieces are pea-size. Sprinkle 1 tablespoon of the water over part of the mixture; gently toss with a fork. Push moistened dough to side of the bowl. Repeat moistening dough, using 1 tablespoon of the water at a time, until the dough is moistened. Divide in half. Form each half into a ball.
On a lightly floured surface, flatten one dough ball. Roll from center to edges into a 12-inch circle. To transfer pastry, wrap it around the rolling pin; unroll into a 9-inch pie plate. Ease pastry into pie plate, being careful not to stretch pastry. Trim bottom pastry to 1/2 inch beyond edge of pie plate.
Roll out remaining pastry to a 12-inch circle and cut into 1/2-inch-wide strips. Fill pastry-lined pie plate with cranberry mixture. Lay half of the pastry strips 1/2 inch apart on top of the filling. Arrange remaining strips 1/2 inch apart on top of the first strips in a diamond-shaped pattern. Trim ends of strips even with edge of bottom pastry. Press ends of strips into crust rim. Fold edge of bottom pastry over edge of strips; seal and crimp edge as desired.
Bake for 40 to 45 minutes or until filling is bubbly and pastry is golden brown. Cool on a wire rack at least 2 hours. Serve warm, or to store, cover and let stand at room temperature for up to 24 hours. Makes 8 servings.