Combine egg and sugar in a bowl, whisking until smooth. Split vanilla bean pod in half lengthwise, and scrape seeds into egg mixture. Whisk in juice blend.
Melt butter in a heavy saucepan over medium heat. Stir in egg mixture, whisking constantly. Bring to a simmer; cook 6 minutes or until thickened, whisking constantly. Chill until ready to serve.
CanoeHouse Restaurant, Mauna Lani Resort, Hawaii