Set your oven's heat to 450 degrees Fahrenheit.
In a small bowl, whisk together the Balsamic Vinegar, Paprika, Onion Powder, Garlic Powder, Dried Thyme, Chili Powder, Crushed Red Pepper, Cumin Powder, Salt, Coriander Powder, and Cayenne Pepper.
Brush all sides of the chicken thigh with sunflower oil, then coat with the seasoning mixture, pressing with your fingers to help the coating adhere.
Heat a large cast iron skillet at high heat until smoking hot.
To blacken the chicken thighs, add them to the pan and cook for 30 to 1 minute on each side.
Place the skillet in the oven for 10 to 12 minutes to complete cooking.
When the chicken is no longer pink in the center, the juices run clear when pierced with a fork, and the internal temperature reaches 160 degrees F, it is done.
Transfer the chicken to a platter, cover loosely with foil to keep it warm, and set aside for 5 minutes before slicing and serving.