In a mixing bowl, whisk together the orange juice, lime juice, olive oil, minced garlic, oregano, cumin, salt, black pepper, and red pepper flakes until well combined.

Reserve 1/4 cup of the marinade for basting later.

Place the chicken thighs in a large resealable plastic bag or a shallow dish.

Pour the marinade over the chicken, ensuring all pieces are well coated.

Seal the bag or cover the dish and refrigerate for at least 2 hours, preferably overnight.

Preheat the grill to medium-high heat.

Remove the chicken from the marinade and discard the marinade.

Place the chicken thighs on the grill, skin side down, and cook for about 6-7 minutes.

Flip the chicken and grill for another 6-7 minutes, basting with the reserved marinade.

Cook until the internal temperature reaches 165°F (75°C).

Remove the chicken from the grill and let it rest for 5 minutes before serving.

Serve with your choice of sides and enjoy!