In a saucepan, combine the milk, heavy cream, and the split vanilla bean. Bring the mixture to a gentle boil over medium heat.
Remove the saucepan from the heat and let it steep for 10 minutes.
Meanwhile, whisk the egg yolks and granulated sugar together for 2 to 3 minutes, or until the mixture becomes pale and creamy.
Remove the vanilla bean from the milk mixture, then gradually whisk the warm milk and cream into the egg mixture.
Wash the saucepan, return the mixture to the clean saucepan, and cook over low heat, stirring constantly, until the custard thickens enough to coat the back of a spoon, about 5 to 10 minutes. Do not let it boil.
Strain the custard through a fine-mesh sieve to remove any lumps.
Refrigerate for at least 12 hours, or until completely chilled.
Freeze the bowl of your ice cream maker for at least 12 hours. Then, following the manufacturer's instructions, churn the chilled custard in the ice cream maker for about 20 minutes, or until it reaches a soft-serve consistency.
Transfer the ice cream to an airtight container and freeze until firm. Serve and enjoy!