In a large bowl, whisk together the orange juice, lime juice, olive oil, minced garlic, cumin, oregano, salt, black pepper, and red pepper flakes (if using).
Add the chicken thighs to the marinade, ensuring they are well coated. Cover and refrigerate for at least 2 hours, or overnight for best flavor.
Preheat your grill or oven to 400°F.
If grilling, place the chicken thighs skin-side down on the grill and cook for about 6-8 minutes. Flip and cook for an additional 6-8 minutes, or until the internal temperature reaches 165°F.
If baking, place the marinated chicken thighs on a baking sheet lined with parchment paper, skin-side up. Bake for 35-40 minutes, or until the skin is crispy and the internal temperature reaches 165°F.
Remove the chicken from the grill or oven and let it rest for 5 minutes before serving.
Garnish with fresh cilantro and serve with rice or a side salad.
Notes
For a smoky flavor, add a teaspoon of smoked paprika to the marinade.
Serve with grilled vegetables or a fresh mango salsa for a tropical twist.