Slice the vanilla bean pod lengthwise and scrape out the seeds.
In a saucepan over medium heat, combine heavy cream, milk, vanilla bean seeds, and pod (or vanilla extract). Heat until it’s steaming but not boiling. This will take a few minutes. Then remove from heat and let it sit for 10 minutes to infuse.
In a large bowl, whisk together egg yolks, sugar, and salt until smooth and pale.
Slowly pour the warm cream mixture into the eggs, whisking vigorously and constantly to prevent curdling. Return the mixture to the saucepan and cook over low heat, stirring constantly with a wooden spoon. Cook until the mixture thickens and coats the back of a spoon (170°F - 175°F, don’t let it boil!). Remove from heat and allow it to rest for 5 minutes.
Pour the ice cream mixture through a fine mesh strainer into a clean bowl to remove any bits of cooked egg. Cover the bowl with plastic wrap and refrigerate for at least 4 hours (or overnight) until fully chilled. SEE TIPS.
Pour the chilled mixture into your ice cream machine and churn according to the manufacturer’s instructions (usually 20-30 minutes). Transfer to a freezer-safe container and freeze for at least 2 hours for a firmer texture.