Super taco is likely a derivative of the super burrito, which is a regular Mission-style burrito (first created in San Francisco) with added guacamole and sour cream. If you simply order a taco at most authentic food trucks and taquerias in California it is likely to be what is referred to as a street taco (seasoned meat, onions, cilantro, add your own salsa). Then they will offer a “super” version with added ingredients. Regular tacos at Americanized Mexican restaurants often come with extra ingredients already included.
5 Likes