Toast the Aromatics: Place a large, dry heavy-bottomed pot or Dutch oven over a medium heat. Add the dried chillies, cumin seeds, peppercorns, and cloves. Toast for 1-2 minutes, moving them around constantly, until they become very fragrant. Be careful not to burn them. Remove the spices and chillies and set aside.

Prepare the Sauce Base: In the same pot, place the quartered onion, whole garlic cloves, and halved tomatoes. Cook for 5-7 minutes, turning occasionally, until they have a nice char in places. Add the toasted chillies back to the pot along with 500ml of water. Bring to a simmer, then turn off the heat, cover, and let the chillies rehydrate for 20 minutes.

Sear the Beef: While the chillies rehydrate, pat the beef chunks dry with a paper towel and season generously with salt. Heat the olive oil in a large frying pan over a medium-high heat. Sear the beef in batches, ensuring you don't overcrowd the pan, until deeply browned on all sides. Set the browned beef aside. This step is crucial for developing deep flavour, a technique well-explained by sites like Serious Eats.

Blend the Sauce: Transfer the rehydrated chillies, onion, garlic, tomatoes, and all the toasting liquid to a blender. Add the toasted spices, apple cider vinegar, and a teaspoon of salt. Blend until completely smooth. If needed, add a splash more water to get it moving.

Simmer the Birria: Return the large pot to the hob. Place the seared beef inside and pour the blended chilli sauce over it through a sieve, pressing on the solids to extract all the liquid. Discard the solids. Add the beef stock, cinnamon stick, and bay leaves. Bring to a gentle simmer.

Slow Cook to Perfection: Reduce the heat to low, cover the pot, and let it simmer gently for at least 3 hours, or until the beef is completely tender and falls apart easily when prodded with a fork.

Prepare for Tacos: Carefully remove the beef from the pot and place it in a bowl. Shred it using two forks. Skim the red-tinged fat from the surface of the consommé and place it in a separate bowl – this is your liquid gold for frying! Season the remaining consommé in the pot with salt to your liking. This will be your dipping sauce.

Assemble and Fry: Heat a large non-stick frying pan or griddle over a medium heat. Dip a corn tortilla into the skimmed beef fat, ensuring it's lightly coated on both sides. Place it in the hot pan. Top one half of the tortilla with a generous amount of shredded beef and a sprinkle of grated cheese.

Get Crispy and Melty: Fry for 1-2 minutes until the bottom starts to crisp up. Fold the empty half of the tortilla over the filling. Press down gently with a spatula and continue to cook for another 2-3 minutes per side, until the tortilla is golden and crispy and the cheese is gloriously melty and bubbling at the edges. What works best for me is to control the heat carefully here to avoid burning the tortilla before the cheese has fully melted.

Serve Immediately: Serve the hot, crispy tacos immediately with small bowls of the warm consommé for dipping. Garnish with finely chopped onion, fresh coriander, and a squeeze of fresh lime juice.