Preheat the oven at 350F (180C).With a fork, make some wholes at the bottom of the pate sablée. Then bake the shell until golden brown, 20-25 minutes.Let cool down completely. In a small sauce pan, bring the lemon juice and the lemon zests to a boil.
In a bowl, mix the eggs, sugar and corn starch.
Pour in the boiling lemon juice constantly mixing.
Put the mixture back on medium heat constantly mixing until the cream gets thicker.
Remove from heat and let it cool.
Add in the cubed butter little by little and mix well.
Fill up the shell with this lemon cream and refrigerate.
In the bowl of a stand mixer, beat the egg whites until it form soft peaks.
Add in the sugar and keep beating for 1 minute.
Scoop or pipe the meringue onto the lemon cream (once firm).
Using a torch, toast the top of the meringue.
