Heat the olive oil in a large Dutch oven over medium high heat. Season the chicken thighs with sea salt and freshly cracked pepper, to taste. Add the chicken to the Dutch oven once it is HOT. Cook one side of the thigh for 3-4 minutes or until golden brown. Remove the chicken thighs from the Dutch oven and place onto a plate. Add the onion, garlic, oregano, and orzo to the Dutch oven then cook, stirring constantly, for 1-2 minutes. Add the lemon zest, lemon juice, and the chicken broth. Place the chicken thighs and juices back into the Dutch oven along with the artichoke hearts, grape tomatoes, and kalamta olives. Sprinkle half of the fresh parsley on top.