Season the meat with salt and pepper and place the dried chiles into a bowl with hot water to rehydrate them
Heat the olive oil in a large skillet and brown the beef cubes. Transfer them to the slow cooker. Make the marinating sauce: into a blender pour the beef broth and add the garlic, rehydrated chiles, chipotles in adobo, vinegar, lime juice, and spices. Blend until smooth. If you need to add more broth, do it a tablespoon at a time.
Add the chopped onion, minced garlic, sauce, and bay leaves to the crockpot on top of the meat. Stir, and cook on high for 4-5 hrs or on low for 8 hrs until the meat is tender enough to be shredded with the use of two forks.
After shredding the beef, return it to the crockpot and mix it with the remaining marinade and rendered juices. The meat should be moist but not have excess liquid.
Serve with corn tortillas and the toppings of your choice.