1. In a small bowl, combine flour and salt; cut in shortening until crumbly. Gradually add 3 tablespoons cold water, tossing with a fork until dough forms a ball.
2. Roll out pastry to fit a 9-in. pie plate. Transfer pastry to pie plate. Trim to 1/2 in. beyond edge of plate; flute edges. Bake at 425° for 12-15 minutes or until lightly browned.
3. For filling, in a large saucepan, combine the sugar, cornstarch, flour and salt. Gradually stir in water until smooth. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes longer.
4. Remove from the heat. Stir a small amount of hot filling into egg yolks; return all to the pan, stirring constantly. Bring to a gentle boil; cook and stir 2 minutes longer. Remove from the heat. Gently stir in butter and lemon peel. Gradually stir in lemon juice just until combined. Pour into the crust.
5. For meringue, in a saucepan, combine 2 tablespoons sugar and cornstarch. Gradually stir in cold water. Cook and stir over medium heat until mixture is clear. Transfer to a bowl; cool.
6. In a large bowl, beat egg whites and vanilla until soft peaks form. Gradually beat in the remaining sugar, 1 tablespoon at a time. Beat in cornstarch mixture on high until stiff glossy peaks form and sugar is dissolved. Spread evenly over hot filling, sealing edges to crust.
7. Bake at 350° for 25 minutes or until the meringue is golden brown. Cool on a wire rack for 1 hour. Refrigerate for at least 3 hours before serving. Refrigerate leftovers. Yield: 6-8 servings.