Pat the meat dry and liberally season with salt. Sear the meat on both sides. Then add it to your slow cooker.
In a blender or large food processor, add half the onion, garlic, chipotle peppers and adobo sauce, diced tomatoes, cumin, paprika, pepper, brown sugar, oregano, cloves, cayenne, lime juice and 1 cup of beef stock. Blend in to a thick sauce.
Pour this sauce over the meat in a slow cooker. Add another cup of beef stock, so the meat is covered. Add the bay leaves and cinnamon stick.
Cook on low for 8 hours. Or on high for 4 hours.
Remove the bay leaves and cinnamon stick. Reserve the stew but remove the meat to a cutting board and shred with two forks.
Dice the remaining half an onion as well as the cilantro.
Dip the tortillas on one side in the stew, aiming for the fat on top. Then pan fry with a little butter or oil. Add the meat and cheese to the tortilla and fold over on one side. Pan fry until the cheese is melted.
Serve with the onion and cilantro and extra lime wedges so you can squeeze a little fresh lime juice over the tacos before eating.