Preheat your fire to medium high temperature (around 375F). Add a dutch oven over the fire to preheat for 3-4 minutes.
Add your chiles and garlic to your dutch oven and let char for 30-45 seconds per side. Once charred, add 2-3 cups of warm water to the skillet and let simmer over the fire for 7-8 minutes. Once simmered, pull out the chiles and garlic and dispose of the excess water. Add your chiles & garlic to a food processor along with all the ingredients for the chile paste. Add 2 tbsp of water to the blender and blend until completely smooth.
Place your cleaned dutch oven over the fire, add a little oil and sear off each side of the cubed lamb until browned. Do this in batches if needed. Finally, add all your lamb to the dutch oven along with the chile paste, beef broth, white vinegar, mexican oregano, cinnamon sticks, bay leaves and lime juice. Cover the dutch oven and let simmer over medium high heat until the lamb is fork tender (about 3.5-4.5 hours). Make sure to skim the top of the sauce of fat as needed.
About 30 minutes before the lamb is done, clean off some coals and add your tomatillos to roast on the fire. Cook for 2 minutes then flip over and cook for another 2 minutes. Once well charred, pull the tomatillos off and add to a food processor along with all the other ingredients for the Habanero tomatillo salsa. Blend until smooth, then set aside.
Once the lamb is tender, pull it off and shred it up. Try to get out any excess stuff like cinnamon sticks and bay leaves in your dutch oven sauce, then let simmer for 3-4 minutes until slightly reduced. Add the shredded lamb back to the sauce and let it gently warm next to the fire.
For your tacos, quickly toast your tortillas over the hot coals until they are lightly charred. Begin by adding a large scoop of shredded lamb from the dutch oven followed by the salsa, pickled onions, chopped cilantro and lime wedges. Serve and enjoy!