01 - Combine flour, salt, and confectioners' sugar in a large bowl. Add cold butter and rub between fingertips until mixture resembles coarse crumbs. Incorporate egg and mix just until a smooth dough forms. Shape into a ball, cover in plastic wrap, and refrigerate for 30 minutes.
02 - Preheat oven to 350°F. Roll out chilled dough to fit a 9–10-inch tart pan. Press dough into pan and prick base with a fork. Line with parchment and fill with pie weights. Bake for 20 minutes, remove weights, then continue baking 10 minutes until lightly golden. Cool completely.
03 - Heat milk and vanilla in a saucepan until just simmering. In a bowl, whisk egg yolks with sugar until pale. Add cornstarch and whisk to combine. Gradually pour in hot milk, whisking constantly, then return mixture to saucepan. Cook over medium heat, stirring, until thickened. Remove from heat, add butter, and blend until smooth. Cover with plastic wrap directly on the surface and chill.
04 - Wash, hull, and slice strawberries as desired.
05 - Spread cooled pastry cream evenly in tart shell. Arrange strawberries neatly on top.
06 - Warm apricot jam and water in a small pan until smooth. Brush over strawberries for a glossy finish.
07 - Refrigerate assembled tart for at least 1 hour to set.