The Mexican dish menudo is a stew of organ meats (usually stomach and tendons) with chiles, and sometimes hominy, often eaten as curative for hangovers. Eating Mexican stews demonstrates convergent evolution with Vietnamese soups: the hot bowl is presented with uncooked vegetables and herbs to doctor up as one eats.
But a distinct flavor comes from the herb chepiche. It is ubiquitous in the Oaxacan market areas, and is intensely aromatic. So, is there a substitute? Sadly, according to Gourmet Sleuth - there isn't. So, it's a novel ingredient worth looking for - the aromatic profile is pretty unique.