In a separate bowl, whisk the flour with the salt. Place the butter in the bowl of your electric mixer, or with a hand mixer, and beat until softened. Add sugar and beat until light and fluffy. Gradually add the beaten egg, beating just until incorporated. Add the flour mixture all at once and mix just until it forms a ball. Flatten the pastry into a disk, cover with plastic wrap, and refrigerate for 15-30 minutes or just until firm (can place in freezer for about 10-15 minutes.)
Lightly butter and flour, or spray with a non-stick vegetable/flour cooking spray, an 10 to 11 inch tart pan with a removable bottom. Evenly pat the chilled pastry onto the bottom and up the sides of the pan. Cover with plastic wrap and place in the freezer for about 15 minutes.
Meanwhile, preheat oven to 400 degrees F (205 degrees C) and place rack in center of oven. Lightly prick bottom of pastry crust with the tines of a fork (this will prevent the dough from puffing up as it bakes). Place tart pan on a larger baking pan and bake crust for 5 minutes. Reduce oven temperature to 350 degrees F (180 degrees C) and continue to bake the crust for about 15 minutes or until dry and lightly golden brown. Remove from oven and place on a wire rack to cool completely before filling. Can be covered and stored for a few days.
notes: This is optional, but after baking crust, whip 1 egg white until lightly frothy. With a pastry brush lightly brush the baked crust. Place crust back into the warm oven until the egg wash is dry and set. This will ensure that they crust doesn’t get soggy when you add the pastry cream. Cool crust on rack.
In a medium-sized heatproof bowl, mix the sugar and egg yolks together. (Don’t let the mixture sit too long or you will get pieces of egg forming.) Sift the flour and cornstarch (corn flour) together and then add to the egg mixture, mixing until you get a smooth paste.
Meanwhile, in a saucepan bring the milk and vanilla bean just to boiling (just until milk starts to foam up.) Remove from heat and add slowly to egg mixture, whisking constantly to prevent curdling. (If you get a few pieces of egg (curdling) in the mixture, pour through a strainer.) Remove vanilla bean, scrape out seeds, and add the seeds to the egg mixture. (The vanilla bean can be washed and dried and placed in your sugar bowl to give the sugar a vanilla flavor.) Then pour the egg mixture into a medium saucepan and cook over medium heat until boiling, whisking constantly. When it boils, whisk mixture constantly for another 30 – 60 seconds until it becomes thick. Remove from heat. (Stir in vanilla extract if using instead of a vanilla bean.) Pour into a clean bowl and immediately cover the surface with plastic wrap to prevent a crust from forming. Cool to room temperature. If not using right away refrigerate until needed, up to 3 days. Beat or whisk before using to get rid of any lumps that may have formed.
Heat the apricot jam or preserves and water in a small saucepan over medium heat until liquid (melted). (Can also heat in the microwave.) Remove from heat and strain the jam through a fine strainer to remove any fruit lumps.
To Assemble Tart:
To remove the tart from the fluted sides of the pan, place your hand under the pan, touching only the removable bottom not the sides. Gently push the tart straight up, away from the sides. The fluted tart ring will fall away and slide down your arm. If you want to remove the bottom of the pan, run a knife or thin metal spatula between the crust and metal bottom, then slide the tart onto your platter.
Spread a thin layer of apricot glaze over the bottom and sides of the baked tart shell to prevent the crust from getting soggy. Let the glaze dry (about 20 minutes). Then spread the pastry cream onto the bottom of the tart shell. Place fruit randomly on top of cream or in concentric overlapping circles, starting at the outside edge. After arranging the fruit, rewarm the glaze, if using, and gently brush a light coat on the fruit. If not serving immediately, refrigerate but bring to room temperature before serving. This fruit tart is best eaten the same day as it is assembled. Cover and refrigerate any leftovers.