Trim fat from chicken thighs. Place the thighs and the rest of the ingredients in a large bowl and mix thoroughly, making sure that chicken thighs are covered with oil and spices really well.
Cover the bowl with a plastic wrap and refrigerate for at least 30 minutes. If you are in a rush, you may skip this step, but the chicken will be more flavorful if you let it marinate in oil and spices.
Preheat a large skillet with a tablespoon of butter over medium-high heat. We find that a non-stick skillet works better if you are after a nice brown color but a cast iron or copper pan will work as well.
Place the chicken thighs on the skillet, one at a time, making sure they are not folded and ensuring that they lay flat on the skillet. Sear chicken thighs for 1 minute or so per side, until nicely browned.
Reduce heat to medium and continue cooking for another 4 minutes, flipping chicken thighs twice during the process.
Reduce heat to medium-low, cover the skillet with a lid and continue cooking for another 3-4 minutes, until fully done (internal temperature 165 F).
Serve with your favorite side dish. Sprinkle with chopped green onions and Italian parsley (optional).