01 - In a large bowl, whisk together apple cider vinegar, olive oil, minced garlic, brown sugar, soy sauce, smoked paprika, ground cumin, ground coriander, chili flakes, salt, and black pepper until well combined.
02 - Add chicken thighs to the marinade and turn to coat thoroughly. Cover and refrigerate for at least 1 hour to develop flavor, optionally longer for best results.
03 - Preheat the oven to 400°F (200°C). Remove chicken from marinade, reserving the marinade for later use.
04 - Heat an oven-safe skillet over medium-high heat. Place chicken thighs skin side down and sear for 4 to 5 minutes until golden brown. Flip and sear the opposite side for 2 minutes.
05 - Pour the reserved marinade over the chicken in the skillet. Transfer to the oven and roast for 25 to 30 minutes, basting once or twice, until cooked through and juices run clear.
06 - Remove the skillet from the oven and let the chicken rest for 5 minutes. Sprinkle chopped parsley over the chicken and serve with lemon wedges if desired.