Heat oven to 275 degrees. Over medium-high heat, toast the dried chiles until fragrant, about two to five minutes. Add stock and simmer for 10 minutes until the chiles soften.
Pour the chiles and stock into a blender and add chipotles and adobo sauce. Blend until smooth.
Heat canola oil in a large Dutch oven over medium-high heat. Generously season the chuck roast with salt and pepper and dust with flour. When the oil begins to shimmer, add the chuck and sear until browned, about five minutes. Carefully flip the beef to the other side and brown.
Remove the beef from the Dutch oven and lower heat to medium. Cook onions until softened, about four or five minutes. Add garlic, cocoa powder, tomato paste, cumin, oregano, smoked paprika, cloves and coriander. Continuously stir for 30 seconds.
Pour in the beer and apple cider vinegar. Use a wooden spoon to scrap up the brown bits from the beef. Simmer for about five minutes to allow the beer to slightly reduce.
Stir in the blended chile mixture to make one cohesive sauce. At this point, if you'd prefer to use a slow cooker, pour the chile sauce into the slow cooker with the bay leaves and cinnamon stick and add the browned beef. Cook on low for eight hours. But if you're braising in the oven, return the beef to the Dutch oven along with the bay leaves and cinnamon stick. Bring to a boil.
Once boiling, cover the Dutch oven and place in the 275-degree oven. Cook until the beef easily shreds with a fork. For a 3-pound roast, this should take about three hours while a 4-pound roast should take about four hours. That said, don't judge the beef's doneness on cooking time. Judge it on whether it's easily shreddable. Chuck roast takes a long time to break down, and not ever roast is identical.
When the beef is ready, move to a cutting board and shred with two forks once cool enough to handle.
This step is optional, but if you'd like to thicken the chile sauce to use with the beef, mix the masa harina with just enough water to make a thick but stirrable paste. Add the masa paste to the chile sauce and bring to a simmer on the stove, constantly whisking. Keep whisking until it thickens to your likening. Start with 2 tablespoons but know you can always add more if you'd still like it a little thicker.
Use the beer-braised Mexican beef for tacos, tostadas, burritos, nachos or any other dish you'd like. Enjoy!