Preheat a cast iron skillet over medium heat and add 2 tablespoons of a high heat oil. It's important to let the skillet get hot before adding the chicken to achieve that perfect sear.
In a small dish, measure out the kosher salt, dried oregano, garlic powder, and ground black pepper. Mix it together thoroughly to create a seasoning blend that will enhance the flavor of the chicken.
Lay out a medium-to-large piece of aluminum foil on the counter and place the chicken thighs on top. If you see any large pieces of fat, carefully trim them off with a sharp knife.
Sprinkle half of the seasoning mixture onto the top of the chicken thighs, ensuring even coverage for maximum flavor.
Using a pair of tongs, gently place the seasoned side of the chicken thighs down in the heated skillet. Sprinkle the remaining seasoning onto the other side, and then cover the skillet with aluminum foil. This helps to reduce splatter and keeps the moisture in.
Cook the thighs for 4 minutes on one side, then carefully flip them over using the tongs. Cook for another 4 minutes on the other side. You should see a nice golden-brown color forming.
While the chicken is cooking, take a knife and cutting board to slice the kalamata olives into fourths, dice the tomatoes, and slice the lemon, making sure to remove any seeds.
Once the chicken thighs have finished cooking on the second side, carefully remove the foil. Pour in the chicken stock and spread the sliced olives and diced tomatoes around the chicken in the pan.
Place a slice of lemon on top of each chicken thigh. Bring the mixture to a boil, which should happen quickly.
Turn the heat down to low, then cover the skillet and let it cook for 10 minutes. The thighs are done once their internal temperature reaches 165°F. Once finished, garnish with parsley if desired, and serve!
