Infuse the Milk: In a saucepan, heat the whole milk and heavy cream until it just begins to simmer. Turn off the heat, add the loose-leaf Hojicha, cover the pan, and let it steep for 15 minutes. Strain the infused milk into a clean bowl, discarding the tea leaves.

Temper the Eggs: In a separate bowl, whisk the egg yolks and sugar until pale and slightly thickened. Slowly drizzle a small ladle of the hot Hojicha milk into the eggs while whisking vigorously to temper them.

Cook the Custard: Pour the egg mixture back into the saucepan with the rest of the milk. Cook over low heat, stirring constantly with a wooden spoon or spatula, until the custard thickens enough to coat the back of the spoon.

Chill and Churn: Strain the custard one final time into a bowl. Cover with plastic wrap pressing directly on the surface to prevent a skin from forming. Chill in the refrigerator for at least 4 hours.

Freeze: Churn the chilled mixture in an ice cream maker according to the manufacturer directions. Transfer to an airtight container and freeze for 2 hours until firm before serving.