Pre-heat the oven to 425°F degrees.

Roll the puff pastry out into a 10-inch x14-inch rectangle that will fit on your baking sheet. Use a paring knife to score the pastry one-inch from each edge of the rectangle. Be careful not to cut all the way through the pastry. Pierce the inside rectangle of the dough several times with a fork to vent it. Brush the puff pastry with the beaten egg wash and transfer the pastry to a baking sheet. Place the baking sheet into the pre-heated oven and bake for 20 minutes on the lower rack of oven. Remove the pastry from the oven and press the inside rectangle down with a flat spatula so that it is lower than the “crust” around the edges of the tart. Transfer the tart shell to a cooling rack and let it cool.

Make the pastry cream. Pour the milk into a medium-sized saucepan. Split the vanilla bean open and scrape out the seeds. Place the seeds in the milk and drop in the scraped vanilla bean. Heat the milk and vanilla to a simmer and turn off the heat. Whisk the egg yolks and sugar together in a bowl until thick ribbons fall from the whisk when lifted. Stir in the flour. Temper the milk into the egg yolks by whisking roughly one third of the milk to the eggs and then slowly pour the egg mixture back into the remaining milk in the pan. Bring the mixture back to the boil and boil for one minute. Remove the pan from the heat. Whisk in the butter. Strain the pastry cream through a fine mesh strainer over a bowl to remove any lumps (and the vanilla bean). Place plastic wrap directly on the pastry cream and chill for at least 3 hours or even a day or two.

Mix the berries together in large bowl. Sprinkle the sugar over he top and toss gently.

Fill the cooled pastry shell with the pastry cream and spread evenly. Top the pastry cream with the berries. Melt the apricot jam in small saucepan or in microwave for about 40 seconds and brush it over the berries. Let the jam set before serving.

Garnish with mint leaves and cut into squares to serve.

Tip: To cool pastry cream faster, spread it out in a baking pan, then cover with plastic wrap and refrigerate until chilled.