Make the Tart Crust:

1. Prepare the dough: In a food processor, pulse together flour, sugar, and salt. Add cold butter cubes and pulse until the mixture resembles coarse crumbs with some pea-sized butter pieces remaining. Add egg yolk and vanilla extract, pulse until combined. If the dough seems dry, add ice water 1 tablespoon at a time until dough just comes together when pressed. Don’t overmix.
2. Chill the dough: Turn dough out onto a work surface, shape into a disk, wrap tightly in plastic wrap, and refrigerate for at least 30 minutes (or up to 2 days).
3. Roll and shape: On a lightly floured surface, roll chilled dough into an 11-inch circle about ⅛-inch thick. Carefully transfer to a 9-inch tart pan with removable bottom, gently pressing dough into the bottom and up the sides. Trim excess dough flush with the top edge. Prick the bottom all over with a fork. Freeze for 15 minutes.
4. Blind bake: Preheat oven to 375°F (190°C). Line the tart shell with parchment paper or aluminum foil, fill with pie weights or dried beans. Bake for 15 minutes. Remove weights and parchment, bake for another 8-10 minutes until golden brown. Cool completely on a wire rack.

Make the Vanilla Custard:

5. Heat the milk mixture: In a medium saucepan, combine milk and cream. Heat over medium heat until steaming and just beginning to simmer around the edges. Remove from heat.
6. Prepare the egg mixture: In a mixing bowl, whisk together egg yolks, sugar, cornstarch, and salt until smooth and pale, about 1-2 minutes.
7. Temper the eggs: Slowly pour about ½ cup of the hot milk mixture into the egg mixture while whisking constantly. This tempers the eggs so they don’t scramble. Gradually whisk in the remaining hot milk mixture.
8. Cook the custard: Pour the entire mixture back into the saucepan. Cook over medium heat, whisking constantly, until the custard thickens and comes to a boil, about 5-7 minutes. Let it boil for 1 minute while whisking (this ensures the cornstarch is fully cooked).
9. Finish the custard: Remove from heat, whisk in vanilla extract and butter until smooth. Strain custard through a fine-mesh strainer into a clean bowl to remove any lumps. Press plastic wrap directly onto the surface of the custard to prevent a skin from forming. Refrigerate until completely chilled, at least 2 hours.

Assemble the Tart:

10. Fill the shell: Once custard is cold, give it a good whisk to smooth it out. Spread the custard evenly into the cooled tart shell, smoothing the top with an offset spatula.
11. Arrange strawberries: Pat strawberries dry with paper towels. Arrange them cut-side down in concentric circles over the custard, starting from the outer edge and working toward the center. Pack them closely for the best presentation.
12. Apply the glaze: In a small bowl, microwave apricot jam with 1 tablespoon water for 20-30 seconds until melted. Strain to remove any fruit chunks. Using a pastry brush, gently brush the warm glaze over the strawberries.
13. Chill and serve: Refrigerate the tart for at least 30 minutes before serving to set everything. Remove the outer ring of the tart pan before slicing. Slice with a sharp knife, wiping it clean between cuts.