Whisk all of the Zoup! Beef Bone Broth, oil, lime juice, garlic, cilantro, cumin, chili powder, salt, and pepper together in a bowl.
Add the steak to a glass or non-reactive baking tray and pour the marinade on top. Ensure both side of the steak are well coated, cover the baking tray with plastic wrap and marinate for 1 to 4 hours. Alternatively, you could marinate in a plastic bag.
Heat a grill on medium-high heat. Cook for 5 to 7 minutes on each side. Remove the steak to a cutting board and let it rest for another 5 minutes.
Use a spoon to mash the avocado and spread a large spoonful or two onto each tortilla. Then, top the avocado with sliced steak, a sprinkle of cotija cheese, some diced onion and fresh cilantro. Squeeze fresh lime juice on top.