I recently moved to the Mission District of San Francisco, which has a huge Mexican and El Salvadoran population, and there I discovered a fun new drink. It’s called atol de elote, and it’s served at a bunch of restaurants and taco trucks around the ’hood. It’s like a sweet, hot corn soup that is drunk as a beverage. I hear there’s a variety that contains chocolate, which is a Mexican rather than an El Salvadoran specialty, but I have yet to find it.
The chocolate version is called champurrado. Atole can actually be flavored with almost anything -- I brought some atole de nuez (nuts, in this case, pecans) to the chowhound picnic one year and it was a big hit. You can find powdered atole mix in a range of flavors in most Mexican markets, although of course it's better when it's made from scratch.