In a medium heavy sauce pan, combine the cream and the half and half. Split the vanilla beans in half lengthwise and, using the tip of a knife, scrape out the small seeds into the cream mixture and drop in the pods. Bring the mixture to a boil, then remove from the heat.
In a large bowl, whisk together the egg yolks and sugar until thickened and pale. Pour in the hot cream mixture and stir until well combined. Strain into a large container and refrigerate until cold. Wash and dry the vanilla pods and reserve for another use.
When the cream mixture is cold, pour it into the bowl of an ice cream maker and freeze according to the manufacturers instructions.
c.1997, M.S. Milliken & S. Feniger, all rights reserved