Combine all dry spices and rub generously over every surface of the chuck roast. Place in slow cooker with beef broth, smashed garlic, and chopped onion. Cook on LOW for 8 to 9 hours or HIGH for 4 to 5 hours until completely fall-apart tender.

Transfer beef to cutting board and shred with two forks discarding large pieces of fat. Add 3 to 4 tablespoons of the cooking liquid to keep the meat moist. Taste and adjust seasoning.

Warm corn tortillas in a dry hot skillet for 15 to 20 seconds per side until pliable. This step is not optional — cold stiff tortillas will crack when rolled.

Preheat oven to 375 degrees F. Spread about 1/2 cup of enchilada sauce on the bottom of a 9x13 baking dish.

Fill each tortilla with about 3 tablespoons of shredded beef and a little diced onion. Roll tightly and place seam-side down in the baking dish.

Pour the remaining enchilada sauce evenly over all the enchiladas making sure the ends are covered. Sprinkle generously with shredded cheese.

Bake uncovered at 375 degrees F for 20 to 25 minutes until cheese is completely melted and the sauce is bubbling around the edges.

Garnish with sour cream, fresh cilantro, sliced jalapeños, and lime wedges. Serve immediately.