Preheat the oven and prepare the tart shell.

In a mixing bowl, combine the all-purpose flour, powdered sugar, fine sea salt, and chilled diced unsalted butter to form a dough.

Add the large egg and lemon zest to the dough and mix until combined.

Roll out the dough and fit it into a tart pan, then chill in the refrigerator.

Bake the tart shell in a preheated oven until golden brown, then let it cool.

In a saucepan, heat the whole milk until boiling.

In a bowl, whisk together the egg yolks, granulated sugar, cornstarch, and fine sea salt.

Gradually add the hot milk to the egg mixture, whisking continuously until combined.

Return the mixture to the saucepan and cook over medium heat, stirring until thickened.

Remove from heat and stir in the unsalted butter and vanilla paste until smooth.

Pour the crème pâtissière into the cooled tart shell.

Arrange the fresh strawberries on top of the crème pâtissière.

Sprinkle the granulated sugar over the strawberries for macerating.

Refrigerate the tart until set before serving.