01 -
Dice the onions. Roughly chop the garlic. Remove stems and seeds from the ancho chiles; slice into smaller pieces for ease of blending.
02 -
Preheat a frying pan over high heat. Season beef chuck roast evenly with salt and pepper. Add olive oil to the pan and sear the beef for 2 minutes on each side until well-browned. During the final side, pour 240 ml of beef stock into the pan to deglaze and release browned bits. Transfer both beef and liquid to the slow cooker.
03 -
Add diced onions, chopped garlic, cilantro leaves, tomato sauce, ancho chiles, cinnamon, cumin, smoked paprika, oregano, thyme, bay leaves, and remaining salt and pepper to the slow cooker. Stir gently to combine. Pour in enough beef stock to mostly cover the beef.
04 -
Set the slow cooker on low for 8 to 10 hours. Cook until beef is fork-tender and easily shreds.
05 -
Lift beef from the cooker and place on a board. Shred with forks, discarding any string. Set shredded beef aside in a bowl.
06 -
Remove and discard bay leaves. Using a slotted spoon, transfer the onions, peppers, and garlic to a blender. Add up to 120 ml cooking liquid if needed and puree until completely smooth. Return blended mixture to the cooker, mixing well. Pour about 120 ml of the prepared sauce over the shredded beef and stir gently to coat.
07 -
Preheat oven to 150°C. Heat a large frying pan over medium-high heat and spray with olive oil. Lightly dip a corn tortilla into the sauce and lay it in the pan. Distribute shredded Oaxaca cheese over the surface, then spoon beef onto half the tortilla. Fold over to form a taco and cook until crisp on both sides. Transfer finished tacos to a baking tray and keep warm in the oven as you finish the batch.
08 -
Serve each taco accompanied by a small bowl of the rich consommé for dipping.