Pat the boneless skinless chicken thighs dry and cut them into ½-inch pieces. Drizzle with avocado oil, season with kosher salt, smoked paprika, and cumin. Chop the white onion and fresh cilantro.

Heat a cast iron skillet over medium-high heat, add the chicken pieces in a single layer and cook undisturbed for 3-4 minutes. Flip and cook for another 3 minutes until the internal temperature reaches 165°F.

Char the corn tortillas directly over a low gas flame for about 20-30 seconds per side until charred, or toast them in a dry skillet on high heat.

Assemble the tacos by laying the charred tortillas flat, filling with seared chicken, chopped onion, fresh cilantro, crumbled cotija cheese, and lime wedges.