Heat the milk and cream: In a saucepan, combine the whole milk and heavy cream. Split the vanilla bean lengthwise and scrape the seeds into the mixture. Heat over medium until it just begins to simmer, then remove from heat.

Whisk the egg yolks and sugar: In a separate bowl, whisk the egg yolks and sugar until pale and slightly thickened.

Temper the eggs: Slowly pour the warm milk mixture into the egg yolks while whisking constantly to prevent curdling.

Cook the custard: Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens enough to coat the back of a spoon (about 5-7 minutes). Do not let it boil.

Strain and chill: Strain the custard through a fine-mesh sieve into a clean bowl. Cover with plastic wrap, pressing it directly onto the surface to prevent a skin from forming. Chill in the refrigerator for at least 4 hours or overnight.

Churn the gelato: Pour the chilled custard into an ice cream maker and churn according to the manufacturer’s instructions until it reaches a soft-serve consistency (about 20-25 minutes).

Freeze to set: Transfer the gelato to an airtight container and freeze for at least 2 hours before serving for a firmer texture.