Step 1

Heat oven to 425°F. In medium bowl, mix 2 1/2 cups flour and the salt. Cut in shortening, using pastry blender or fork, until mixture forms coarse crumbs the size of small peas. Sprinkle with water, 1 tablespoon at a time, tossing with fork until all flour is moistened and pastry almost leaves side of bowl (1 to 2 teaspoons more water can be added if necessary). Gather pastry into a ball. Divide pastry in half, and shape into 2 rounds on lightly floured surface. Wrap flattened rounds in plastic wrap, and refrigerate about 45 minutes or until dough is firm and cold, yet pliable. This allows the shortening to become slightly firm, which helps make the baked pastry flaky. If refrigerated longer, let pastry soften slightly at room temperature before rolling.

Step 2

In large bowl, mix sugar, 1/2 cup flour and the orange zest. Stir in rhubarb and strawberries. Using floured rolling pin, roll one round of pastry on lightly floured surface (or pastry board with floured pastry cloth) into round 2 inches larger than upside-down 9-inch glass pie plate. Fold pastry into fourths, and place in pie plate, or roll pastry loosely around rolling pin and transfer to pie plate. Unfold or unroll pastry and ease into plate, pressing firmly against bottom and side and being careful not to stretch pastry, which will cause it to shrink when baked. Add filling mixture. Dot with butter.

Step 3

Trim overhanging edge of pastry 1/2 inch from rim of plate. Roll out second pastry round. Fold into fourths, and place over filling, or roll loosely around rolling pin and place over filling. Unfold or unroll pastry over filling. Cut slits in pastry so steam can escape. Trim overhanging edge of top pastry 1 inch from rim of plate. Fold edge of top crust under bottom crust, forming a stand-up rim of pastry that is even thickness on edge of pie plate, pressing on rim to seal; flute edges.

Step 4

Cover edge with 2- to 3-inch strip of foil to prevent excessive browning. Bake on parchment-covered baking sheet 20 minutes. Reduce oven temperature to 350°F. Remove foil, and continue to bake 35 to 50 minutes or until crust is golden brown and juice begins to bubble through slits in crust. Serve warm or cool.