The ingredients are simple?beer, cheese, and spices?and the result is delicious. Still, beer cheese is a rarefied dish not common in cookbooks or on menus. Since the 1940s, this creamy appetizer with a kick, traditionally served with pretzels, has quietly found its way into pubs and restaurants throughout the South and Midwest. The original recipe is cloaked in a mystery nearly as deep as the JFK assassination. Ask most makers and they'll act demure about the contents of their dip. Some refuse to disclose what kind of beer or cheese they use or which extra spices they add. Others keep their preparation instructions secret.