In a large saucepan combine milk and heavy cream. Split vanilla bean lengthwise. Using a small paring knife, scrap out seeds and then put seeds and pod into milk mixture. Bring to a boil over medium heat. Remove from heat and allow flavors to steep for 30 minutes. Meanwhile, in a medium stainless steel bowl, combine yolks and Sugar, whisk for 2 to 3 minutes until it reaches a pale yellow color, and Sugar is dissolved. Variations: vanilla Honey: Replace Sugar with 3/4 cup Honey. vanilla rosewater: Add 1 1/2 teaspoons rosewater to mixture when it is cooled.