Pour the creams into a heavy saucepan, place over medium-low heat and heat until barely simmering, stirring frequently. Turn the heat down to low.
Whisk together the egg yolks, sugar and salt in a large bowl until thoroughly combined.
Slowly pour about 1/2 cup of hot cream mixture into the egg yolk mixture, whisking constantly. Repeat three times more, whisking thoroughly before adding each additional 1/2 cup of hot cream to the egg yolk mixture.
Pour the egg yolk mixture back into the saucepan with the remaining hot cream and whisk constantly over medium-low heat until the mixture thickens and will coat the back of a spoon, 5 to 8 minutes. Do not let mixture boil.
Pour the ice cream base into a bowl and allow to cool for about 20 minutes; place in refrigerator and chill overnight. The next day pour into an ice cream maker and freeze according to the manufacturer's directions. Remove the ice cream, pack into a covered container and freeze for 2 hours or overnight before serving.