Combine all marinade ingredients in a large bowl or zip-top bag and add the steak, ensuring it is well-coated.
Seal and refrigerate for at least 2 hours, though 4 hours is ideal to let the lime juice tenderize the meat.⏱ 120 min
Remove the steak from the marinade and pat it thoroughly dry with paper towels to ensure a good sear.
Preheat your outdoor grill to high heat or place a heavy cast-iron skillet over high heat until it is smoking hot.
Grill or sear the steak for 3-5 minutes per side until deeply charred on the outside and medium-rare inside.⏱ 5 min
Transfer the meat to a cutting board and let it rest for 10 minutes to keep the juices inside.⏱ 10 min
Dice the steak into small, bite-sized cubes, cutting against the grain for maximum tenderness.
Warm your tortillas in a dry skillet or over an open flame until they are soft and lightly toasted.
Assemble tacos by dividing the steak among the tortillas and topping with diced onion, fresh cilantro, and salsa.
Serve immediately with extra lime wedges on the side.