In a large bowl, whisk together lime juice, olive oil, minced garlic, cumin, chili powder, smoked paprika, dried oregano, salt, and pepper. Add the chicken thighs, ensuring they are evenly coated. Cover and let them marinate for at least 30 minutes, or overnight for best results.

Preheat your grill or skillet over medium-high heat. Once hot, add the marinated chicken. Cook for about 5–7 minutes on each side, or until the chicken is cooked through and has a nice char (165°F internal temperature).

Once cooked, remove the chicken from the heat and let it rest for 5 minutes. After resting, slice the meat into thin strips or small bite-sized pieces.

Heat up your corn tortillas in a dry skillet or directly over a gas flame for about 20–30 seconds per side until they are warm and slightly charred.

Layer the sliced chicken in each warm tortilla and top with chopped onion, fresh cilantro, and a generous squeeze of lime juice. Add the optional toppings for a perfect finishing touch.