Traces of 2,500-year-old chocolate on a plate in the Yucatan peninsula may mean chocolate was a condiment or sauce with solid food in pre-Hispanic cultures rather than as a beverage reserved for the elite.

Or it could have spilled. 

The discovery announced by Mexico's National Institute of Anthropology and History also suggests that there may be ancient roots for traditional dishes eaten in today's Mexico, such as mole, the chocolate-based sauce often served with meats. The traces of chemical substances considered "markers" for chocolate were found on fragments of plates uncovered at the Paso del Macho archaeological site in Yucatan in 2001 and recently analyzed.

Mexican archaeologists find that Mayans may have used chocolate as spice 2,500 years ago by Mark Stevenson, Associated Press