01 - In a mixing bowl, combine flour, salt, and powdered sugar. Add diced cold butter and rub together using fingertips until the mixture resembles coarse meal. Incorporate the egg until a smooth dough forms. Shape 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- or 10-inch tart pan. Prick the base with a fork, cover with parchment paper and baking weights. Bake for 20 minutes. Remove weights and parchment, then continue baking for 10 minutes until lightly golden. Set aside to cool.
03 - Heat milk with vanilla bean (split and scraped) or extract over medium heat until just simmering. Meanwhile, whisk egg yolks with granulated sugar, then add cornstarch until smooth. Slowly pour a little hot milk into the yolk mixture, whisk, then return everything to the saucepan. Cook, whisking constantly, until thickened. Remove from the heat and add butter. Cover directly with plastic wrap and cool completely.
04 - Rinse, hull, and slice strawberries as desired.
05 - Spread cooled pastry cream evenly in the cooled tart shell. Arrange strawberries decoratively over the cream.
06 - Heat apricot preserves with water until smooth, then brush over the strawberries for a glossy finish. Refrigerate for at least 1 hour before serving.