Heat cream, sugar and split vanilla bean over med heat until simmering. Remove from heat, cover and steep 30 minutes. Remove vanilla bean.
Meanwhile place egg yolks in medium bowl.
Put cream mixture back on heat. Heat mixture again to simmering and slowly whisk 1 cup of the hot cream mixture into egg yolks then add yolk mixture to cream mixture and heat to 160 degrees or until slightly thickened.
Remove from heat and add milk and chai. Chill to room temperature and then refrigerate to cold before freezing in an ice cream maker.