Marinate the chicken: In a large bowl, mix olive oil, lime juice, garlic, cumin, chili powder, paprika, oregano, salt, and black pepper until well combined. Add the chicken thighs and toss them thoroughly so every piece is fully coated. Cover and let it marinate for at least 15–30 minutes so the flavors soak in properly.
Cook the chicken: Heat a skillet or grill pan over medium-high heat. Add a small amount of oil, then place the chicken in the hot pan. Cook for about 6–8 minutes per side until the outside is nicely browned with slight charring and the inside is fully cooked and juicy.
Rest and chop: Remove the chicken from the pan and let it rest for a few minutes so the juices settle inside the meat. After resting, chop the chicken into small, taco-sized pieces for easy filling.
Warm the tortillas: Warm the corn tortillas on a dry skillet for about 20–30 seconds per side until soft and flexible. Keep them wrapped in a clean towel so they stay warm while you finish preparing everything.
Assemble the tacos: Add chopped chicken into each tortilla, then top with diced onions, fresh cilantro, and a spoonful of salsa or pico de gallo. Finish with a squeeze of lime juice right before serving for a fresh, zesty flavor.