Generously rub both sides of the flank steak with the mixed spices.
Whisk together the pressed garlic, olive oil, and lime juice.
Place the flank steak in a large bowl and pour the marinade over it. Cover with plastic wrap and let it marinate in the refrigerator for 2-4 hours.
Preheat the grill to high heat and cook the marinated steak to your liking (rare, medium-rare, or medium-well). I prefer mine medium-well and it cooked for about 4-5 minutes per side. Remove the steak from the grill and cover with foil for about 10 minutes.
Cut the steak into thin strips and place it into the corn tortillas. Add any topping of your choice. I added homemade Mexican salsa, red onion, avocado, iceberg lettuce, sour cream, cilantro, and queso fresco.
Don't rush the marinade- This is important for the tenderization of the meat so let it sit for at least 2 hours. It will reduce the chewiness of the meat if you can let the salt and lime juice work on it.
Don't overcook it- Flank is a lean cut of meat and it can get dry when overcooked. Keep it to a medium or medium-well at the most and cut it thinly against the grain.
Rest the meat- When meat is cooked, the juices are pulled to the surface by the heat. Letting it rest covered in foil keeps it warm while the juices are reabsorbed for a moister steak. Cutting it beforehand will let the juices run out.
Warm the tortillas- Make sure to warm the tortillas on the grill alongside the steak for the best flavor and to make them more malleable for easy filling.