01 - Split the vanilla bean lengthwise and scrape out the seeds. Place the seeds and pod into a saucepan along with the milk and heavy cream. Warm over medium-low heat until the mixture begins to steam gently, without reaching a boil. Remove from heat and steep for 15 minutes.
02 - In a mixing bowl, whisk the egg yolks and sugar together vigorously until the mixture turns pale yellow and falls in thick ribbons from the whisk.
03 - Remove the vanilla pod from the cream mixture. While whisking the yolks continuously, slowly pour the warm cream in a thin stream to temper the eggs. Return the combined mixture to the saucepan and cook over low heat, stirring constantly with a wooden spoon, until the custard thickens enough to coat the back of the spoon and registers 175°F on an instant-read thermometer. Do not allow it to boil.
04 - Pour the custard through a fine-mesh sieve into a clean bowl to catch any cooked egg bits. Let it cool to room temperature, then cover and refrigerate for at least 2 hours until completely chilled.
05 - Pour the chilled custard into an ice cream maker and churn according to the manufacturer's instructions until it reaches a soft-serve consistency.
06 - Transfer the churned ice cream to a freezer-safe container with a tight-fitting lid. Freeze for at least 3 hours or until firm throughout.
07 - Let the ice cream sit at room temperature for 5 to 10 minutes before scooping to soften slightly for easier serving.