Bring a pot of water to a boil and add the guajillo peppers to rehydrate
Cub sirloin and tri-tip and season with salt and pepper
In a food processor or blender, combine chipotle peppers with adobo sauce, apple cider vinegar, tomatoes, garlic, oregano, smoked paprika, ground cumin, onion powder, fennel seeds and rehydrated guajillo peppers. Process until smooth
Add meat and marinade to a large bowl and cover to marinate for at least 10 hours
Once ready to cook, melt butter in a large pan over medium heat and sauté onion until translucent (you can do this on the stovetop, or in your slow cooker or instant pot)
Add meats, marinade, bay leaves, cloves and cinnamon stick as well as just enough chicken stock to completely cover meat
On the Stovetop, simmer over low heat for 4 to 6 hours
For a Slow Cooker, cover and cook on low for 5-6 hours or let it go during your work day
If you're going the Instant Pot route, you'll only need about 45 minutes on high
Remove the meat and shred
Strain the leftover stew through fine-mesh colander
Heat oil over medium heat in a skillet. Use more oil if needed to ensure the entire bottom of the skillet is generously covered
Dip tortillas in strained stew, back with shredded cheese and meat and fry on each side once pan is hot
Garnish with cilantro and cotija