In a medium mixing bowl, stir together 1 1/4 cups flour and the 1/4 teaspoon 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 the side of the bowl. Repeat moistening dough, using 1 tablespoon of the coldwater at a time, until all dough is moistened. Form into a ball. Pre heat oven to 450 degree F.
Roll dough into a 12-inch circle. Transfer to a 9-inch pie plate. Trim pastry to 1/2 inch beyond edge of pie plate. Crimp edge. Generously prick bottom and sides of pastry with fork. Line pastry with a double thickness of foil. Bake for 8 minutes. Remove foil. Bake 5 to 6 minutes more or until golden brown. Cool on a wire rack. Set aside.
Separate egg yolks from whites; set whites aside for meringue, letting egg whites stand at room temperature for 30 minutes. Meanwhile, for filling in a saucepan combine sugar, 3 tablespoons flour, cornstarch, and dash salt. Gradually stir in 1-1/2 cups water. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes more. Remove from heat.
Slightly beat egg yolks with a fork. Gradually stir about 1 cup of hot filling into yolks. Pour egg yolk mixture into remaining hot filling in saucepan. Bring to a gentle boil. Cook and stir 2 minutes more. Remove from heat. Stir in lemon curd, butter, and lemon peel. Keep filling warm. Reduce oven to 350 degree F.
Prepare meringue for pie. In a large bowl combine egg whites, vanilla, and cream of tartar. Beat with an electric mixer on medium speed about 1 minute or until soft peaks form (tips curl). Gradually add sugar, 1 tablespoon at a time, beating on high speed about 4 minutes more or until mixture forms stiff, glossy peaks (tips stand straight) and sugar dissolves.
Pour warm lemon filling into baked pastry shell. Use a pastry bag with a large star tip to pipe meringue in rows over warm filling, sealing to edge. Bake for 15 minutes or until merignue begins to turn golden brown. Cool on a wire rack 1 hour. Chill 3 to 6 hours before serving. Cover for longer storage. Makes 8 servings.