Season both sides of the chicken with salt and pepper. Heat oil in a heavy cast iron skillet over medium-high heat. Add chicken skin side down and cook for about 5-8 minutes. Do not touch the chicken for the first couple of minutes. Once the chicken is easy to move and not sticking, you can move it while checking the skin side. Keep cooking skin down until you get a dark golden skin.
Then, flip the chicken thighs, and move the skillet to oven. Cook for another 7-10 minutes, until done.
Transfer to a plate, lightly cover with foil and rest for at least 5-6minutes before serving.
