Step 1In a medium saucepan, warm the milk, salt and sugar, stirring to dissolve the sugar. Scrape the seeds from the vanilla bean and add them to the saucepan, then drop in the pod. Cover, remove from the heat and set aside to steep at room temperature for 30 minutes.
Step 2Pour the cream into a medium bowl and set a mesh strainer on top.
Step 3Reheat the milk mixture until it’s warm. In a separate bowl, whisk the egg yolks, then gradually add some of the warm milk mixture, whisking constantly as you pour. Pour the warmed yolks back into the saucepan.
Step 4Cook over low heat, stirring constantly and scraping the bottom of the pan with a heatproof spatula until the custard is thick enough to coat the spatula. Pour the custard through the mesh strainer into the heavy cream. Rinse the vanilla pod and return it to the custard to continue steeping. Stir in the vanilla extract.
Step 5Set the bowl containing the custard over a larger bowl of ice water. Stir the custard until cool, then cover and refrigerate until thoroughly chilled.
Step 6Remove the vanilla pod, rinsing and reserving it for another use, and then freeze the chilled custard in your ice cream maker according to the manufacturer’s instructions.
To make stracciatella, melt 5 ounces of bittersweet chocolate until smooth, then drizzle a very thin stream of the warm chocolate over one quart of the ice cream during the last possible moment of churning. If the chocolate clings too much to the dasher, remove the ice cream from the machine and drizzle the chocolate into the frozen ice cream by hand while you layer it into the storage container, breaking up any chunks as you stir.