Directions

1. Preheat oven to 350F.
2. In a medium saucepan, combine sugar, flour, cornstarch, salt, water, lemon juice, and zest. Heat mixture while stirring until it reaches a boil.
3. Remove from heat and stir in the butter.
4. In a medium bowl, temper the lemon mixture into the egg yolks a little at a time to prevent cooking egg yolks. Then put the entire mixture back into the pan over medium heat. Stir while cooking for 2-3 minutes.
5. Pour pie filling into a pre-cooked pie crust and smooth the surface.
6. In Mixing Bowl, beat egg whites and cream of tartar on high speed until foamy. Beat in sugar, one tablespoon at a time, scraping the sides of the bowl occasionally. Continue beating until stiff, glossy peaks form and sugar is completely dissolved.
7. Spoon meringue onto filling, spreading to the edge of the crust.
8. Bake 10 to 15 minutes, or until meringue is browned and temperature reaches 160F. Cool on cooling rack for 1 hour. Refrigerate about 4 hours before serving.