Preheat the oven to 350°F (180°C), or 160°C fan oven.

In a medium bowl, whisk together flour, sugar and salt. Add melted butter and using a spatula, mix until combined.

Add ⅔ of the flour mixture to a 9-inch (23 cm) tart pan with a removable bottom. Using your hands and the flat bottom of a measuring cup, press the mixture evenly into the bottom of the pan and just starting up the sides. Press the remainder of the mixture into the fluted sides, connecting to the bottom crust. Use your hands to make sure the crust is evenly spread in the edges of the pan, even on top, and with the aid of the measuring cup, even on the bottom. The measuring cup can be used to ensure the joint of the sides and bottom are straight against the pan.

Line the crust dough with parchment paper or aluminum foil and fill with pie weights, dried beans or rice work well. Bake the crust for 15 minutes, remove the paper and weights, and continue to bake for an additional 10 minutes. Carefully remove from the oven and set on a cooling rack.

In a medium bowl, whisk eggs and egg yolks together and set aside.

In a small saucepan, whisk together sugar, cornstarch, salt, and lemon zest. Add lemon juice and butter and cook on medium heat, stirring often until the mixture just starts to bubble.

Remove the pan from heat and slowly pour the lemon mixture into the eggs, whisking constantly. Transfer curd to a new small or medium saucepan, whisking constantly over medium-low heat until the curd starts to thicken and coat the back of a spoon, this takes several minutes.

Place a fine-meshed sieve over a medium-sized bowl and strain the curd into the bowl. Stir in the cream and pour the curd into the warm crust.