This Birria Tacos Recipe is definitely one that you need to try! Slow cooked shredded beef and Oaxaca cheese are melted together in corn tortillas in a pan. Then all of that goodness is dipped into the most unbelievable ancho chile sauce for one delicious bite after another. My version uses a slow cooker to cook the beef roast to melt-in-your-mouth perfection and blends the sauce right in a blender. It's super easy to toss the ingredients together and let the slow cooker do all the work!
Dice the onions, rough chop the garlic, remove/discard the stems from the dried chiles and shake out the seeds. Discard the seeds and cut the chiles into 2-3 pieces each (will get pureed once cooked, so this is just to fit into slow cooker).
SEAR BEEF. Preheat a frying pan or skillet on high heat. Season your chuck roast with salt, and pepper to coat all sides. Drizzle the olive oil in the hot pan and add the beef and sear for 2 minutes on each side to brown evenly. On the final side, pour 1 cup of the beef stock in the pan to scrape up the browned bits from the bottom of the pan. Transfer the beef to the slow cooker and pour in the liquid from the pan.
SLOW COOKER. To the slow cooker with the beef, add the onions, garlic, cilantro leaves, crushed tomatoes, chiles, cinnamon, cumin, paprika, salt, pepper, oregano, thyme, and bay leaves. Stir to combine. Then add the beef. Pour in the rest of the beef stock until it reaches the top of the beef. Set the slow cooker to 8 or 10 hours, depending on your schedule.
SHRED BEEF. When the cooking time is done, transfer the beef using tongs to a platter or cutting board. Shred the beef with forks and discard any string that may have been tied around the roast. Transfer the beef to a bowl and set aside.
BLEND SAUCE. Fish out the bay leaves and discard. Using a slotted spoon, scoop out all of the onions and ancho peppers and transfer to a blender. (alternatively, you could strain the liquid into another bowl, add then add onions and peppers to the blender.) Blend the onions and the peppers until smooth. If needed, add 1/2 cup of the cooking liquid to the blender to help smooth it out. Once smooth, pour it back into the liquid in the slow cooker and stir to combine. Finally, pour 1/2 cup of this sauce over the beef and gently stir to mix through.
Preheat the oven to 300 F degrees. Preheat a large frying pan or skillet on the stove medium-high heat. Spray the pan with olive oil and then take 1 corn tortilla and dip it lightly into the sauce, then place it in the oiled hot pan. Sprinkle cheese evenly over the entire tortilla, then top half of the tortilla with the shredded beef.
Using a spatula, gently fold over the cheese-only side of the tortilla over the beef side. With the spatula, transfer the folded taco to a sheet pan and keep in the oven as you assemble and cook the rest of the tacos, each taco getting transferred to the oven as finished.
Serve each taco with a small bowl of the dipping sauce.