If using a large cut of beef, trim any excessive fat and cut it into robust 2-inch pieces. This allows the meat to easily absorb the cooking liquid and seasonings. Place the beef chunks and the chopped onion and minced garlic directly into the bottom of your slow cooker.

In a separate bowl, whisk together the beef broth, lime juice, lime zest, chili powder, cumin, smoked paprika, dried oregano, salt, and pepper. This pre-mixing step ensures the flavors are evenly distributed before they hit the meat.

Pour the spice and broth mixture evenly over the beef and aromatics in the slow cooker. Ensure the meat is mostly submerged. Secure the lid tightly. Cook on LOW for 6 to 8 hours, or on HIGH for 3 to 4 hours. The goal is for the meat to be easily shredded with two forks, transforming tough cuts into tender bites.

Once the cook time is complete, carefully transfer the beef chunks from the slow cooker to a large cutting board using a slotted spoon. Reserve the cooking liquid (the rich consomé) in the slow cooker. Use two forks to shred the meat completely.

For the ultimate street taco texture, transfer the shredded meat to a baking sheet. Toss the meat with about 1/2 cup of the reserved cooking liquid to keep it moist. Broil on high for 3-5 minutes, until the edges of the beef are slightly caramelized and crispy, mimicking that authentic outdoor cooking experience.

Warm your mini corn tortillas in a dry skillet for 30 seconds per side until pliable and slightly charred, or quickly fry them in a little butter for extra flavor. Fill each tortilla with the slow-cooked beef, then top immediately with fresh cilantro, diced onion, cotija cheese, salsa verde, avocado slices, and a squeeze of lime.