This is as close to a certain big chain's barbacoa meat I have ever made! It is full of intense flavors such as garlic, cayenne, and sweet, smoky chipotle. Make sure you scale down the cayenne and serrano if you can't handle heat because this recipe is packin' lots of it! Serve on corn or flour tortillas garnished with cilantro and topped with lime cilantro rice (from this website), black beans, pico de gallo, guacamole, cheese, lettuce, and sour cream.
I cook everything extremely spicy so my addition of cayenne and serrano peppers may or may not be spicy to you. If I was a normal person this measurement might be different but written as is it's very hot!