In a shallow dish or zip-top bag combine lime juice, olive oil, soy sauce, minced garlic, ground cumin, chili powder, smoked paprika, kosher salt, and black pepper. Whisk or shake until blended.

Marinate the steak

Trim excess fat from the steak if desired. Place the steak in the marinade, turning to coat thoroughly. Marinate at room temperature for 20–30 minutes or refrigerate for up to 2 hours. Remove from fridge 15 minutes before cooking to come toward room temperature.

Cook the steak

Heat a cast-iron skillet or heavy pan over high heat until very hot (or preheat a grill to high). Add a thin film of oil to the pan if using. Sear the steak 3–4 minutes per side for medium-rare (internal temperature ~130–135°F / 54–57°C) depending on thickness. For medium cook a minute or two longer per side. Avoid overcooking — steak should be juicy. Remove steak to a cutting board and rest 5–7 minutes.

Slice the steak

Using a sharp knife, slice the steak thinly across the grain into bite-sized strips about 1/4-inch thick. Keep warm.

Onions & peppers (optional)

While the steak rests, slice the yellow onion into thin strips and core and slice the bell pepper into similar strips. Heat 1 tablespoon oil in a skillet over medium-high heat. Add onions and peppers, sprinkle 1/2 tsp kosher salt, and sauté 5–7 minutes until softened and slightly charred at the edges. Remove from heat and keep warm. (If you prefer plain raw onions, skip sautéing and use finely diced white onion from toppings.)

Tortillas & assembly

Warm the corn tortillas: heat a dry skillet over medium-high heat. Warm each tortilla 20–30 seconds per side until pliable and lightly charred in spots. Keep wrapped in a clean towel to stay warm.

Assemble the tacos: place 2–3 slices of steak on each warm tortilla. Top with sautéed onions and peppers if using (or raw diced white onion), sprinkle with chopped cilantro, and crumble queso fresco. Spoon salsa over the top and finish with a squeeze of lime. Add hot sauce if you like more heat.

Serve

Serve the tacos hot with extra lime wedges and salsa on the side. Enjoy.