For an even richer flavor, consider searing the brisket in rendered beef fat instead of avocado oil. If you prefer a spicier barbacoa, add an extra chipotle pepper or a pinch of cayenne pepper to the sauce. This barbacoa is excellent served with warm tortillas, cilantro-lime rice, and your favorite toppings like avocado, salsa, and queso fresco. The brisket can be made a day or two in advance. Store it in the cooking liquid in the refrigerator, and reheat before serving.