A delicate French custard sauce.
Place a metal bowl in a shallow dish of cold water.
Combine the milk and vanilla in a large saucepan over medium-low heat. Warm just until small bubbles begin to appear around the edges. Remove from heat.
Whisk together the sugar and yolks in a medium bowl. Very slowly whisk in half of the hot milk to temper. Return the mixture the the saucepan and cook over medium heat, stirring constantly until thickened slightly.
Pour the mixture into the prepared cold bowl, optionally straining to remove any solids. Scrape the seeds from the vanilla bean into the sauce, stirring to distribute. Serve immediately or refrigerate until cold.
Cooked longer to thicken more this time. Over cooked (did not boil) and got very slightly chunky, so we used an immersion blender to smooth it out again. Turned out quite well - keeps shape when spooned onto a plate and very tasty.
Made a half batch (but used full bean). I do not think I cooked it long enough as it's quite thin after cooling, even after refrigerating it is still just a liquid. Despite this, it is very tasty over bread pudding.
Made this for Christmas bread pudding again.