Season the chicken with 2 tsp salt and ½ tsp black pepper, then leave to marinate in the refrigerator for at least 4 hours or up to 24 hours.
Preheat the oven to 350°F (175°C). Remove chicken from the refrigerator and pat dry.
Heat 2 tbsp olive oil in a large oven-safe pan over medium heat. Sear chicken skin for about 10 minutes until the skin is golden brown. Flip and cook for 1-2 minutes. Remove chicken to a plate.
Drain all but 1 tbsp of oil from the pan. Add garlic cloves and sauté for 1 minute.
Deglaze the pan with chicken stock. Stir in oregano, thyme, red pepper flakes, and lemon juice.
Return chicken to the pan. Cover and bake for 20-30 minutes, or until the internal temperature reaches 165°F (74°C).
Remove chicken. Place the pan back on low heat, add capers, and slowly whisk in the cold butter, a few cubes at a time, until the sauce emulsifies.
Return chicken to the pan or transfer to a platter and spoon sauce over. Garnish with chopped parsley and serve.
Note: Deglazing: making a gravy or sauce by adding liquid to the cooking juices and food particles in a pan in which meat has been cooked.