This flan recipe has taken many attempts and required lots of input from expert sources (cookbooks, pastry chef friends, les Epices Roellinger for the vanilla bean), but it finally meets all my criteria for taste (not too sweet), texture (firm, but not rubbery), kitchen economy (whole eggs, not a zillion yolks), and appearance (a touch of turmeric for color).
1¼ cups flour
2 Tbs./30 g. sugar
¼ tsp. salt
3 1/2 oz./7 Tbs./100 g. cold butter, cut into pieces
1/3 cup cold water
1 quart whole milk
1 vanilla bean (or ½ high-quality vanilla bean like one from Les Epices Roellinger)
¾ cup/150 g. sugar, divided
¾ cup/100 g. cornstarch
tiniest pinch of turmeric, optional
To make the Crust: Whisk together the flour, sugar, and salt in a bowl. Cut or rub the butter into the flour mixture until it resembles coarse meal. Make a well in the center of the flour-butter mixture, pour the water into the well, and stir the mixture until a dough forms. Add 1 to 2 tsp. more of water, if necessary. Shape the dough into a flat, round disk, wrap in a kitchen towel or plastic wrap, and refrigerate at least ½ hour. (Longer is better.)
Brush an 11-inch/28-cm tart pan with removable bottom or an 11-inch/28-cm flan ring with melted butter.
Roll out the chilled dough to a 13-inch/33 cm circle on a floured work surface. Press the dough into the pan or flan ring, and place on a baking sheet. Prick the bottom of the crust all over with a fork, and chill or place in the freezer at least 15 minutes.
To make the Custard: Pour the milk into a large saucepan. Split the vanilla bean in half lengthwise, and scrape out the seeds with the back of a paring knife. Add the seeds and the vanilla bean halves to the milk along with ¼ cup/50 g. of the sugar. Place on the stovetop, and bring to a boil.
While the milk is coming to a boil, whisk together the remaining sugar, cornstarch, and turmeric. Whisk in the eggs until the mixture is very smooth.
Remove the boiling milk from the heat, and whisk about 1 cup into the egg mixture, to temper it. Whisk the remaining milk in to the egg mixture. Return the custard to the saucepan, and cook 1 minute over medium heat, whisking constantly. It should thicken. The moment it begins to boil, remove the custard from the heat, and remove the vanilla bean halves. Spread the custard in the prepared crust. (Yes, while it is still raw.) Let the flan cool at least ½ hour and up to 2 hour before baking so that it forms a skin.
Preheat the oven to 425˚F/210˚C. Bake the flan 20 minutes. Reduce the oven temperature to 350˚F/180˚C, and bake 15 to 20 minutes more, or until the flan has turned dark brown on the top and the crust is golden brown. Cool completely before unmolding and serving.