Step 1: Prepare Lemon Filling

Preheat oven to 350 F. In a saucepan whisks together sugar, flour, cornstarch, and salt. Then add water, lemon juice and stir it. Cook over medium-high heat, stirring frequently until the mixture comes to a boil. Then add butter, lemon zest, egg yolks and stir it. Bring to a boil and continue to cook while stirring constantly until thick. Remove saucepan from heat and cool completely. Pour lemon filling into baked pie crust.

Step 2: Make Meringue

To make the meringue, in a large bowl, whip egg whites until foamy. Add sugar and continue to whip until stiff peaks form. Spread meringue over lemon filling.

Step 3: Bake and Serve Lemon Meringue Pie

Bake in preheated oven for 10 minutes, or until meringue is golden brown. Remove from the oven and place it on the wire rack. Let it cool for 15 minutes. Serve with lemon sliced and mint leaves.