In a large mixing bowl, combine the fresh orange juice, lime juice, olive oil, minced garlic, onion powder, achiote powder, oregano, cumin, sea salt, and black pepper. Whisk until fully blended.

Add the chicken thighs to the marinade and ensure each piece is coated. Cover with plastic wrap and marinate for at least 30 minutes at room temperature or up to 2 hours in the refrigerator.

Preheat a nonstick skillet over medium heat and add olive oil to prevent sticking. Once shimmering, add the marinated chicken.

Cook the chicken thighs for about 5 minutes without moving them, allowing a caramelized crust to form.

Flip the chicken thighs using tongs and cook for an additional 5 minutes until golden brown.

Reduce heat to medium-low, check the internal temperature with a meat thermometer, aiming for 165°F (75°C).

Remove the chicken from the skillet and let it rest for about 5 minutes before slicing or serving whole.