Gather all your ingredients and tools: beef strips, tortillas, spices, vegetables, a skillet, knife, and mixing bowl.
Mix paprika, cumin, chili powder, and a squeeze of lime in a bowl to create your spice blend. Rub this mixture onto the beef strips evenly, then set aside to marinate briefly.
Heat your cast iron skillet over medium-high heat until it’s hot and begins to shimmer, releasing a faint smoky aroma.
Add the beef strips to the skillet, spreading them out in a single layer. Sear for about 3-4 minutes without moving them, allowing a deep caramelization to develop.
Flip the beef strips and cook for another 4-5 minutes, until they are cooked through and slightly charred around the edges. Drain any excess fat if necessary.
While the beef cooks, warm the tortillas in a dry skillet or microwave until soft and pliable—about 30 seconds.
Chop the tomatoes and onion into small dice, then toss with a pinch of salt and a squeeze of lime juice in a bowl for a fresh topping.
Assemble each taco by placing a handful of beef on a warm tortilla, then topping with shredded lettuce, diced tomatoes, onions, and a drizzle of salsa if desired.
Squeeze fresh lime over the assembled tacos to brighten flavors and add a zesty finish.
Serve immediately while the tortillas are warm and the beef is juicy, enjoying the bold flavors and satisfying textures.
