In a medium saucepan, combine milk and cream over medium-high heat.
Scrape vanilla bean seeds into pan, add the pod as well.
Heat over medium heat, just until mixture starts to bubble around the edges of the pan, about 2 minutes.
Remove from heat; cover and let stand 15 minutes.
In a medium mixing bowl, whisk the egg yolks with sugar.
Pour a small amount of the hot milk mixture into the egg mixture, then whisk to combine.
Add more of the milk mixture, and whisk to combine.
Pour this mixture into the remaining cream mixture in the pan.
Cook over medium heat, stirring constantly until custard is thick enough to coat the back of a spoon, about 5 to 7 minutes.
Strain through a fine sieve into a medium bowl to remove the vanilla pod over an ice-water bath. Let stand until cold, stirring occasionally.