tuile cookie "chips"
2 T butter
1/4 C powdered sugar
1/4 C cake flour
1 egg white
1 pinch salt
seeds from 1/4 vanilla bean
1 C milk
2-3 T sugar, depending on how sweet you want it
1/4 vanilla bean pod, minus the seeds you used for the tuile cookies
1 T cornstarch
1 egg yolk
Preheat your oven to 300 degrees F. Melt the butter and mix in the powdered sugar. Mix in the egg white; I used a small blender for this. Stir in the flour, making sure not to overmix.
Screw tuile stencils; those take too long. Spread the goo thinly and evenly on a pan lined with parchment or nonstick foil, using something long and straight. Score it with a sharp knife to make triangles. Bake until the edges start to brown and the cookies look dry. Quickly slice along the score lines and lift the cookies with a spatula, draping them over something if you want them to have a curved shape. They'll stiffen as they cool, and they cool fast.
Mix the milk with the cornstarch, then pour it into a pan along with the vanilla bean pod and heat it over medium low, whisking often. Add the sugar to the egg yolk in a small container and stir vigorously until the egg yolk turns lighter colored and the mixture gets runnier/fluffier. Keep whisking the milk and cornstarch in the pan every so often, more as it heats up. When it starts to bubble, it should thicken. When the milk and cornstarch are thick enough to coat the back of a spoon, remove the pan from the heat.
Scoop out a little of the hot milk and stir it into the egg yolk mixture. Scoop out a little more and stir again. Don't add it all at once or you'll curdle your egg yolks. When you've added at least half of the hot milk to the egg yolk and stirred thoroughly, you can pour the egg yolk mixture back into the pan over low heat. Whisk this stuff constantly. You want a smooth custard, not curdled egg yolks floating in milk. When it reaches at least 170 degrees F and is a little thicker, remove it from the heat. Pour into small dishes and chill.
Serve the tuile cookies with the custard dipping sauce.