From David Lebovitz, makes approximately 1litre
1 cup whole milk
3/4 cup sugar
1 vanilla bean
2 cups heavy cream
7 large egg yolks
1 teaspoon vanilla extract
In a saucepan over medium heat, combine the milk, salt and sugar. Split the vanilla bean in half and scape out the seeds. Add both the seeds and the pod to the milk mixture. Remove from heat and set aside.
Place a large bowl over an ice bath. Pour the cream into the bowl.
In a separate bowl, whisk together the egg yolks. Pour some of the warm milk mixture into the eggs, whisking constantly. Transfer the yolks into the sauce pan and stir to combine with the remaining milk. Cook over medium-low heat until the mixture thickens to form a custard that will coat the back of a spatula. Stir constantly, making sure to scrap the bottom of the saucepan.
Add the custard to the heavy cream. Stir over ice until combined. Add the vanilla extract.
Refrigerate until chilled thoroughly or overnight.
Remove the vanilla bean pod and transfer the custard to the ice cream maker. Freeze mixture according to ice cream maker instructions.