Mix flours and salt in large mixing bowl. Cut in margarine and shortening until mixture resembles small peas. Add water and mix just until pastry come away from sides of bowl. Turn onto floured surface and knead 3 or 4 times. Cover and chill at least 30 minutes before using. Four double-crust pies, bake as directed in each recipe. To make baked pie shells, roll out 1/2 of pastry at a time and line 9-inch pie tin. Chill 15 minutes. Line pastry with 2 layers of tissue paper larger than pie shell and fill pie shell with dried beans. Bake at 425° 12 minutes or until browned. Remove beans by lifting out tissue paper; discard. Cool pie shell before filling. Makes enough for 1 9-inch double-crust pie or 2 9-inch pie shells.
Note: To make pastry in food processor, put flours and salt in processor work bowl. Cut margarine and shortening into about 10 pieces each and add to bowl. Turn machine on and off about 8 or 9 times, or until mixture resembles small peas. Add water and process until pastry forms a ball. Remove from machine and knead a couple of times. Cover and chill at least 30 minutes before using.