ok, im in highschool, and I have a few mexican friends. Often times they bring there own food. Most evry time it is either some kind of salad(skuzzy your right) here anyway, but other times they bring a beef and beef burrito( yes some mexicns have beef).
When I read this psot i asked them, they said something like this: ususally we just have some kind of veggitables. We grow our own plants, herbs and things like that. But also when we get the chance we go to the market and get some meet, and stuff.
So this is what I think( while mexican food is mainly a mix, they often have to resort to veggies like historical food, thanks.