Preheat oven to 425 degrees.

Combine flour and salt in a small bowl, then cut in shortening until crumbly. Gradually add 3 tablespoons cold water, tossing with a fork until dough forms a ball.

Roll out pastry to fit a 9″ pie plate. Transfer pastry to pie plate. Trim to 1/2″ beyond edge of plate; flute edges. Bake for 12-15 minutes or until lightly browned. Remove from oven, and lower the oven temperature to 350 degrees.

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.

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.

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.

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.

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.