>> muchas gracias. >> i mean, that's as old-school as it gets. this is super ancient. >> a finer dish than this one you cannot have. this is something that you do not find anywhere else in mexico. >> a quiet night in the zocalo, the central square of oaxaca. ♪ but even tonight there's plenty of evidence of the struggle, the discontent boiling just under the surface. the graffiti and painting of this street artist who goes by