Remove the stems and seeds from the guajillo and ancho chiles. Rinse the chiles under cool running water, rubbing the surfaces to remove any dust.
8 dried (56 g) guajillo chiles, 4 dried (48 g) ancho chiles
Place the chiles in a heatproof bowl and cover with the hot water. Set a small plate over the chiles to keep them submerged. Soak for 20 to 25 minutes, or until soft and flexible. Drain well and discard the soaking water.
4 cups (960 ml) hot water
Pat the pork shoulder dry with paper towels and season evenly with the salt and black pepper. Preheat the oven to 325°F (163°C).
3 pounds (1.36 kg) boneless pork shoulder, 2 tsps (6 g) kosher salt, 1 tsp (2 g) ground black pepper
Heat 1 tablespoon (15 ml) of the avocado oil in a large Dutch oven over medium-high heat. Add half of the pork in a single layer and brown for 2 to 3 minutes per side, until browned on several sides. Transfer the browned pork to a plate. Leave the remaining seasoned pork uncooked. Browning half of the pork creates enough fond for the red chile sauce without having to sear all 3 pounds (1.36 kg) in batches.
2 tbsps (30 ml) avocado oil
Reduce the heat to medium and add the remaining 1 tablespoon (15 ml) avocado oil. Add the onion and cook for 5 to 6 minutes, stirring occasionally, until softened. Add the garlic and cook for 30 seconds.
½ large yellow onion, 6 large cloves garlic
Pour ½ cup (120 ml) of the chicken broth into the Dutch oven and scrape the bottom with a wooden spoon to loosen the browned bits. Transfer the onion, garlic, broth and browned bits to a blender.
2½ cups (600 ml) low-sodium chicken broth
Add the softened guajillo and ancho chiles, chipotle peppers, remaining 2 cups (480 ml) chicken broth, 1 tablespoon (15 ml) vinegar, brown sugar, oregano, cumin and cloves. Blend for 1 to 2 minutes, or until the red chile sauce is smooth and no large pieces of chile skin remain.
3 chipotle peppers in adobo sauce, 2 tbsps (30 ml) white vinegar, 1 tbsp (13 g) packed light brown sugar, 2 tsps (2 g) dried oregano leaves, 2 tsps (4 g) ground cumin, ¼ tsp (0.5 g) ground cloves
Pour the chile sauce through a fine-mesh strainer set over a bowl, pressing it through with a spoon or flexible spatula. Discard the solids remaining in the strainer.
Return the Dutch oven to medium heat. Pour in the strained chile sauce and bring to a simmer, stirring frequently.
Add the browned pork, uncooked pork and any accumulated juices to the Dutch oven. Add the bay leaves and stir to coat the pork in the sauce. Return to a gentle simmer.
2 bay leaves
Cover the Dutch oven and transfer to the oven. Braise for 1½ to 2 hours, stirring once after about 1 hour. Begin checking the pork at 1½ hours. The carne adovada is ready when a fork slides easily into the pork and the pieces pull apart with light pressure without completely falling apart.
Remove the Dutch oven from the oven and discard the bay leaves. Stir in the remaining 1 tablespoon (15 ml) vinegar. Taste and adjust the salt, if needed, before serving.