• Prepare the all-butter pie crust according to the instructions and let rest in the fridge as instructed.
• Preheat the oven to 350 degrees
• Roll out 1 disc of all-butter pie crust and place in a pie dish that has been sprayed with non-stick spray.
• Poke all over the crust with a fork. Cover lightly with foil and place pie weights on top. You can also use uncooked rice if you do not have pie weights.
• Bake for 10 minutes.

Lemon Filling

• In a saucepan, add all but the egg yolks in the lemon filling: 1 1/3 cup water, 1 cup granulated sugar, 1/4 cup cornstarch, 1/4 tsp fine sea salt, 1/2 cup fresh lemon juice, 1 tbsp lemon zest and 2 tbsp unsalted butter. Turn the heat on medium-high and allow the mixture to reach a boil.
• While the mixture heats up, in a small bowl, add the four egg yolks, reserving the egg whites for the meringue. Whisk the yolks together in the small bowl.
• Once the mixture reaches a boil, stir periodically and allow it to boil for 3 minutes. Turn off the heat.
• Now, it's time to temper the egg yolks in. Using a small 1/4 measuring cup, carefully scoop out the boiling liquid. With your other hand, whisk the egg yolks as you allow a slight drizzle of hot liquid to drip into the egg yolks. Go slow and whisk fast so you don't cook the eggs.
• Once the 1/4 cup of liquid is added, repeat with a second 1/4 cup of boiling mixture.
• After the 1/2 cup has been added to the egg yolks, but your whisk in the saucepan and slowly pour the egg yolk mixture into the hot lemon mixture while whisking.
• Turn the heat back on and whisk while the lemon mixture reaches a boil again. Whisk until it feels thicker, then remove from the heat. This should only take a few minutes. Set aside while you prepare the meringue.

Meringue

• In the bowl of a standing mixer add the 4 egg whites, 1/2 tsp of cream of tartar, 1/2 cup of granulated sugar and 1/8 tsp fine sea salt. With the whisk attachment, beat on high speed until stiff peak. This takes 6-9 minutes.

Assemble

• Pour the warm lemon filling into the partially baked pie crust from earlier.
• Spoon the meringue on top of the lemon filling.
• Place in the preheated oven and bake for 20 minutes.
• Remove and allow the pie to cool to room temperature before serving. You can also place in the fridge for a few hours before serving as well.