Barbacoa is cooked in a spicy marinade made from chiles, onions, garlic, herbs, and spices. After cooking until very tender, the meat is shredded with extra marinade before it is served with corn tortillas.
Guajillo chiles have very fruity, floral notes. Substituting will result in a completely different flavor profile.
EQUIPMENT: cast iron skillet, tongs, blender, Instant Pot