01 - Combine flour, salt, and powdered sugar in a mixing bowl. Add cold diced butter and rub together with fingertips until texture resembles coarse crumbs. Incorporate egg and mix just until dough forms. Shape into a disc, wrap in plastic, and refrigerate for 30 minutes.
02 - Preheat oven to 350°F. Roll out dough and line a 9-10 inch tart pan. Pierce base with a fork. Cover with parchment paper and fill with pie weights. Bake for 20 minutes. Remove weights and paper, bake 10 minutes more until lightly golden. Cool completely.
03 - Heat milk with vanilla until just simmering. In a bowl, whisk egg yolks and sugar, then add cornstarch. Gradually whisk in a portion of hot milk. Return mixture to saucepan and cook over medium heat, stirring until thickened. Remove from heat, incorporate butter. Cover cream with plastic wrap directly on surface and cool.
04 - Wash, hull, and slice strawberries as desired.
05 - Spread cooled pastry cream evenly into tart shell. Arrange strawberry slices decoratively over cream.
06 - Warm apricot jam with water until fluid. Gently brush strawberries with glaze to impart shine.
07 - Refrigerate assembled tart for at least 1 hour before serving to set.