01 - Combine flour, salt, and powdered sugar in a mixing bowl. Cut in the cold butter using fingertips until the mixture resembles coarse crumbs. Add the egg and blend just until the dough comes together. Form into a ball, wrap in plastic, and chill for 30 minutes.
02 - Preheat oven to 350°F. Roll out the chilled dough and line a 9-10 inch tart pan. Prick the base with a fork, cover with parchment paper and pie weights. Bake for 20 minutes. Remove weights and parchment, then bake for an additional 10 minutes until lightly golden. Let cool completely.
03 - Heat milk with vanilla (split and scraped if using a bean) until just simmering. In a bowl, whisk egg yolks with sugar, then blend in cornstarch. Gradually add some hot milk to temper, whisking constantly. Return mixture to saucepan and cook over medium heat, stirring continuously, until thickened. Remove from heat and stir in butter. Cover with plastic wrap directly on the surface and cool completely.
04 - Wash, hull, and slice the strawberries as desired.
05 - Spread the cooled pastry cream evenly in the cooled tart shell. Arrange the strawberries neatly over the cream.
06 - Gently heat apricot jam with water until melted. Brush over the strawberries for a glossy finish.
07 - Refrigerate the assembled tart for at least 1 hour before slicing and serving.