In a bowl, combine minced garlic, olive oil, lime juice, balsamic vinegar, cilantro, cumin, chili powder, salt, and pepper. Coat the steak with the marinade, making sure it's fully covered. Let it marinate for at least 30 minutes at room temperature, or up to 8 hours in the fridge for deeper flavor.
It’s best to keep the steak at about 1,5 to 2 cm (1/2 to 3/4 inch) thick for optimal cooking. You can also slice it in horizontally before marinating to achieve even cooking.
Heat a grill pan or skillet over medium-high heat. Once hot, cook the steak for about 4-5 minutes per side for medium-rare (adjust depending on your preference). After cooking, let the steak rest for 5 minutes, then slice it thinly against the grain.
Heat the small piece of charcoal directly on the stove until it's red hot and pace it in a small piece of aluminum foil, shaped it into a tiny cup, in the pan next to the cooked steak. Then drizzle 1 tsp of olive oil (or ghee) over the charcoal. The charcoal will start to smoke immediately.
Quickly cover the pan with a lid or foil to trap the smoke. Let the steak sit in the smoke for 5-10 minutes to absorb the smoky flavor.
Take the sliced steak and place it into the warm tortillas. Top with freshly chopped cilantro, white onion, and a squeeze of lime juice. Add salsa and avocado slices if desired. Serve immediately with extra lime wedges on the side.
