San Antonians are an especially stubborn lot when it comes to Mexican food; we have our firmly held opinions, our favorite places ... and, frequently, our black holes of utter ignorance. Just as an unconverted outsider might find it strange that otherwise rational people would seek out a dark and dingy dining room for the express purpose of eating leathery enchiladas filled with yellow cheese, topped with thin, chile gravy, and strewn with chopped, raw onion, so do we compadres in crime have trouble imagining a world in which Mexican cuisine is as subtle and sophisticated as any on the planet. This is a wake-up call, y'all: There is a wonderful world of food beyond that narrow strip that is Carlos Fuentes' MexAmerica. Picante Grill is one way to get from here to there.;- Ron Bechtol