Directions

1. In a bowl, combine flour and salt; cut in shortening and butter until crumbly. Gradually add water, tossing with a fork until dough forms a ball. Divide in half. Roll each portion into a 5-in. circle. Transfer to two 10-oz. custard cups. Press dough 1-1/8. up sides of cups. Place on a baking sheet. Bake at 425 degrees F for 7-10 minutes or until golden brown.
2. In a saucepan, combine sugar, cornstarch and salt. gradually stir in cold water until smooth. Cook and stir over medium heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes more. Remove from the heat. Stir half of hot filling into egg yolk; return all to the pan. Bring to a gentle boil; cook and stir for 2 minutes. Remove from the heat; stir in lemon juice and butter. Pour into pastry shells.
3. In a small mixing bowl, beat egg white and cream of tartar on medium speed until soft peaks form. Spread evenly over hot filling, sealing edges to crust. Bake at 350 degrees F for 15-20 minutes or until meringue is golden brown. Cool on a wire rack for 1 hour; refrigerate for at least 3 hours before serving.