Beef Barbacoa Lettuce Wraps

Ingredients

• 3 lb boneless beef chuck roast, cut into 4 large chunks
• 1 3/4 tsp fine sea salt, divided
• 1/2 tsp freshly ground black pepper
• 3 dried ancho chiles
• 1 1/2 cups beef bone broth, divided Label: beef bones, water, vegetables, herbs, and salt, with no sugar, natural flavors, or oil
• 1 tbsp avocado oil
• 1 medium white onion, roughly chopped
• 8 cloves garlic, peeled
• 1 jalapeño, stemmed (seeded for less heat)
• 3 tbsp apple cider vinegar
• 6 tbsp fresh lime juice (about 4 limes), divided, plus wedges to serve
• 2 tsp ground cumin
• 2 tsp dried oregano, Mexican if you can find it
• 1/4 tsp ground cloves
• 1/4 tsp cayenne, or to taste
• 3 bay leaves
• 1 small red onion, thinly sliced, for pickling
• 2 to 3 romaine hearts, leaves separated
• 2 ripe avocados, sliced
• 1/2 cup cilantro leaves

Instructions

1. Season the beef: Pat the chuck dry and rub it all over with 1 1/2 teaspoons of the salt and the pepper. Even 30 minutes on the counter gives the salt time to dissolve and start working into the meat, so it seasons the beef below the crust.
2. Toast and soak the chiles: Pull the stems off the anchos, split them open, and shake out the seeds. Heat a large skillet over medium heat and press the chiles flat against it for 15 to 20 seconds a side, until pliable and fragrant, then put them in a heatproof bowl. Pull them the moment they smell toasty, because a scorched chile turns the sauce bitter. Heat 1 cup of the broth in the skillet until it simmers, pour it over the chiles, and let them soak for 20 minutes, until soft. The hot broth softens the skins and carries their flavor into the liquid you will blend.
3. Sear the beef: Wipe out the skillet, add the avocado oil, and heat it over medium-high until it shimmers. Sear the chuck for 3 to 4 minutes a side, until deeply browned all over, and move it to the slow cooker. The browned crust adds a roasted, savory flavor that the moist heat of a slow cooker never builds on its own.
4. Blend the sauce: Pour the remaining 1/2 cup of broth into the hot skillet and scrape up the browned bits. Put the chiles and their soaking broth in a blender with the skillet broth, the chopped white onion, garlic, jalapeño, vinegar, 2 tablespoons of the lime juice, cumin, oregano, cloves, and cayenne, and blend on high for a full minute, until smooth. Pour the sauce over the beef in the slow cooker and tuck in the bay leaves.
5. Slow-cook: Cover and cook on low for 8 to 9 hours or on high for 5 to 6 hours, without lifting the lid, until the beef pulls apart easily with a fork. The chuck passes 145°F (63°C), the safe temperature for whole cuts of beef, early in the cook; it needs hours near 200°F (93°C) for its connective tissue to melt into gelatin and turn the meat tender.
6. Pickle the onion: About 30 minutes before serving, toss the red onion with 1/4 cup of the lime juice and the remaining 1/4 teaspoon of salt in a small bowl. Press it down and let it sit, stirring once, until it turns bright pink and softens. The lime's acid tames the onion's raw bite.
7. Shred and serve: Lift the beef onto a board, pull out the bay leaves, and spoon most of the fat off the top of the sauce. Shred the beef with two forks, return it to the slow cooker, and stir it through the sauce, then let it sit for 10 minutes on warm so the shreds soak up the juices. Taste and add salt or lime. Spoon the beef into romaine leaves and top with avocado, pickled onion, and cilantro, with lime wedges on the side.