To prepare lemon filling: In a medium saucepan, mix 1 cup of sugar with flour, cornstarch, and salt. Add water, lemon juice, and lemon peel. Cook over medium-high heat, stirring often, until the mixture starts boiling. Add butter and mix. Put the egg yolks in a small bowl and slowly mix in 1/2 cup of the hot sugar mixture. Mix the egg yolk mixture back into the sugar mixture. Heat until boiling and keep cooking while stirring until it thickens. Take it off the stove. Put the filling into the cooked pastry crust.
To prepare meringue: In a big glass or metal bowl, beat egg whites until they become frothy. Add sugar little by little and keep beating until the mixture forms stiff peaks.
Put the meringue on top of the pie, making sure to seal the edges with the crust.
Put in the oven that has been preheated for 10 minutes, or until the meringue turns golden brown.
Have fun!
