Making the Birria de Res
Bring the meat to room temperature for about 30 minutes and then sprinkle liberally on all sides with kosher salt.
In a large Dutch oven over medium high heat, add your vegetable oil. When the oil is shimmering hot, carefully place the chuck roast and short ribs in. Don't crowd the pan, do it in batches if needed, and sear on all sides until browned. Repeat with all the pieces of chuck roast and the short ribs until every piece of meat is well browned. Set meat aside on a plate or in a large bowl for later.
in a large pan or skillet, dry toast the whole spice: the cumin seeds, coriander seeds, cloves, black peppercorns, and cinnamon stick over medium heat. Place all the spices in an even layer across the pan, then give the pan a nice, gentle shake to ensure the spices get evenly toasted. They're done once they smell super fragrant, about 3 minutes. Set the spices aside.
In a large pan (you can use the pan from toasting the spices), add the dried guajillo and ancho chiles, the large white onion quarters, garlic cloves, all the spices except the bay leaves and cinnamon stick, and pour enough cold water in to cover everything. Place over medium heat and simmer gently for about 15 minutes.
Pour the chilies, onion, garlic, and spices through a mesh strainer and discard the liquid, then transfer all the solids and toasted spices, chipotle peppers, oregano, pureed tomatoes, apple cider vinegar, and a cup of the beef broth to a high powered blender. Blend until smooth.
Add the seared meat, the blended chili sauce, the bay leaves and cinnamon stick, and 9 cups of beef broth to the dutch oven and stir well. Let simmer over medium-low heat, covered, for 3 to 4 hours or until the meat is fork-tender, stirring to ensure the bottom doesn't burn every hour or so.
Serving Birria Tacos
Remove the meat from the consomme, shredding all of it with forks and removing the bones.
Use a large spoon to skim some of the fat off the top of the braising liquids and into a shallow dish. This fat is what you'll dip the tortillas into to fry them with.
Pour some of the consomme into a small serving bowl and add the chopped cilantro.
Heat a plancha or cast iron skillet to medium heat. Use tongs (or clean fingers) to dip both sides of a tortilla into the fat in your shallow dish. Place it flat onto the skillet and add a little birria meat and Oaxaca cheese to one side of the tortilla. Fold the tortilla, and let cook for about 30 seconds to a minute, then flip and cook for another 30 seconds so the other folded side gets crispy as well.
Move the cooked birria quesataco to a serving plate and repeat until you have enough tacos for serving immediately with consomme, diced onions, limes, and cilantro.
Reserve the rest of the birria meat, the consomme, and the fat in their own separate airtight containers in the fridge for up to five days. This can also be done as a make ahead meal. Simply do Step 4 and Step 5, melting some of the cooled fat in the nonstick pan and cooking the tortillas and meat as written.