Preheat your Traeger Grill to 225°/Super Smoke.
While the grill heats, coat the beef roast with lemon and lime juice and then season heavily with your selected rub.
Place the meat directly on the grate of the grill and allow to cook for 90 minutes.
Arrange dried peppers on a cookie sheet, and place cookie sheet and sliced onions directly on the grill. Allow to cook for 30 minutes.
Remove peppers and onions from grill, put in a Dutch oven pot and sumberge in boiling water. Allow to sit for 15-20 minutes.
Using scissors, remove stems and some seeds from the soaked peppers. Place in the vessel of a blender along with the sauce ingredients through apple cider vinegar.
Blend on high until very smooth. Then transfer back to the Dutch oven.
Remove roast from Traeger and place in the sauce. Add some more beef broth to thin out the sauce and cover the roast.
Stir in the last sauce ingredients (bay leaf, cinnamon stick, cloves and cumin seeds).
Cover Dutch oven and return to the grill at 300°.
Cook for 2-4 hours until the beef is fork tender and temperature is between 205° and 210° internally.
Transfer the beef to a tray for shredding.
Pour the sauce through a mesh sieve to strain and return strained sauce to the stove to keep warm.
Preheat Traeger Ranger with a cast iron griddle (or your other Traegers with a griddle in it) on high until very hot.
Assemble tacos by dipping tortillas in the strained sauce, then placing them on a lightly oiled griddle.
Cook until starting to bubble, then flip and cover with cheese.
Add shredded beef and fold over, continuing to cook until everything is hot and melty.
Serve tacos on a platter with hot consomme/sauce, and dressed with toppings like diced jalapenos, diced onions, diced tomatoes, chopped cilantro, avocado chunks and wedges of lime.