Step 1

Add heavy cream, sugar and lemon zest to a medium or large saucepan and bring to medium heat. Stir constantly until sugar is fully dissolved. Stop stirring briefly to allow the mixture to come to a simmer. Be careful to only let it reach a simmer (just a few bubbles on the surface) and do not let it come to a boil. Let it simmer for exactly 1 minute, stirring a few times so that the milk does not curdle. This is very important, see notes for more details. Remove mixture off from the heat and let it cool for about 5-10 minutes.

Step 2

After 5-10 minutes, add in the lemon juice. Whisk until the lemon juice is evenly incorporated. The mixture should thicken slightly. Pour the mixture through a strainer into the graham cracker crust.

Step 3

Place pie into the fridge for several hours to set. For best results, let it set overnight. Once pie is set you can decorate the pie if you would like. I piped fresh whipped cream on top. Keep pie in fridge. About an hour before serving, put the pie into the freezer. Bring pie out of the freezer only when ready to serve. Cut the pie with a large sharp knife while it is still frozen and plate slices while pie is frozen. It will only take a few minutes for the pie to thaw and come to room temperature but freezing the pie will make it much easier to cut and plate the slices because of the delicate nature of the graham cracker crust. If you are using a sturdier thicker crust like a shortcrust pie crust then you don't need to freeze the pie beforehand (though you still can). Pie is best enjoyed cold. The filling will start to weep a little if left out in warm temperatures too long.