Alabama Sweet Potato Meringue Pie

In medium bowl, mix flour and 1/2 teaspoon salt. Cut in margarine or butter, and shortening until mixture resembles coarse crumbs. Sprinkle 3 to 4 tablespoons cold water, 1 tablespoon at a time, into flour mixture, mixing lightly with a fork after each addition until dough is just moist enough to hold together. Shape dough into a disk. On lightly floured surface, with floured rolling pin, roll dough into a round 2 inches larger all around than inverted 9 1/2-inch deep-dish pie plate. Gently ease dough into pie plate, trim edge, leaving 1-inch overhang. Fold overhang under, pinch to form decorative edge. With fork, prick bottom and side of piecrust in many places to prevent puffing during baking. Cover and refrigerate at least 30 minutes. Meanwhile, preheat oven to 425 degrees F. In 2-quart saucepan, heat sweet potatoes and enough water to cover to boiling over high heat. Reduce heat to low, cover and simmer 10 minutes or until sweet potatoes are fork-tender. Drain and mash sweet potatoes (you should have about 2 cups). Line piecrust with foil and fill with pie weights, dry beans, or uncooked rice. Bake piecrust 10 minutes, remove foil with weights and bake 10 minutes longer or until lightly browned. If pastry puffs up during baking, gently press it to pie plate with back of spoon. Cool piecrust on wire rack at least 10 minutes. Turn oven control to 375 degrees F. In large bowl, with wire whisk, beat mashed sweet potatoes with egg yolks, brown sugar, half-and-half, molasses, cinnamon, nutmeg, and 1/2 teaspoon salt until blended. Cover and refrigerate egg whites until ready to use. Pour sweet-potato mixture into cooled crust. Bake pie 55 to 60 minutes, until knife inserted 1 inch from edge of pie comes out clean. Transfer pie to wire rack while preparing meringue. Turn oven control to 400 degrees F. In small bowl, with mixer at high speed, beat egg whites and cream of tartar until soft peaks form, gradually sprinkle in sugar, 2 tablespoons at a time, beating until whites stand in stiff peaks. Spread meringue over hot filling to edge of crust, swirl meringue with back of spoon to make attractive top. Bake 10 minutes or until meringue is golden. Cool pie on wire rack. 10 servings.