In a rocks glass half-filled with ice, add vodka, Kahlua, and eggnog. Supermarket eggnog is marginal; home-made high-octane eggnog is preferable. Stir well and serve.
Concocted years ago by A. Hunter Dale and re-discovered in 2004 by Mathew Barlow during Xmas in Salt Lake City. We like to think The Dude would approve.