Whisk the egg yolk and cream together in a small bowl and set aside.

Measure the flour into a large bowl then add the salt and sugar. Whisk together then add the cubed butter. Work the butter in with a pastry cutter or your clean hands.

Once you have a crumbly mixture with roughly pea-sized pieces of butter throughout, drizzle in the yolk cream mixture and mix together with a fork or knife. Transfer the dough onto a piece of plastic, press and fold together, then shape into a disk, wrap and chill for about an hour.

Roll the dough into a circle then transfer to a 9 or 10 inch tart pan (one with a removable base is preferable). Press into the pan then dock the bottom and trim the edge. Freeze for about 30 minutes.

Preheat your oven to 375F then bake for about 20 minutes or until a light golden color, then reduce the oven temperature to 350F. Make the curd while the shell bakes.

In a medium bowl combine the eggs and yolks then whisk together and set aside.

Zest two lemons then squeeze ½ cup of juice, then add the zest, juice, butter, and sugar to a medium sized pot and place over medium heat. Stir often until the butter is melted and the mixture just starts bubbling, then remove from heat and slowly drizzle into the egg mixture while whisking vigorously.

Pour back into the pot and place over low heat, whisking constantly until the mixture thickens and just starts to bubble, about 170F. Your curd is done once it coats the back of a wooden spoon.

Strain into a bowl and cover the surface with plastic wrap.

Pour the curd into your tart shell and smooth the surface, then bake for 10 minutes or until the edge is just set. Refrigerate for 2 hours then cut and serve.