- Preheat oven to 375 F. 
- Heat some cooking fat in an ovenproof skillet and season the chicken thighs with salt and pepper. - Cooking fat, Sea salt and freshly ground black pepper 
- Brown the chicken for 2 to 3 minutes per side; set aside. - 6 to 8 chicken thighs 
- Lower the heat and add the olive oil to the same skillet used for the chicken. - ¼ cup olive oil 
- Add the carrot, celery, onion, and garlic, and cook for 2 to 3 minutes. - 1 onion, 2 to 3 carrots, 2 celery stalks, 2 garlic cloves 
- Pour in the chicken stock and bring to a simmer until evaporated by half. - 1 cup chicken stock 
- Add the diced tomatoes, tomato sauce, tomato paste, lemon zest, parsley, oregano, and thyme; season everything to taste. - 2 cups tomatoes, ½ cup tomato sauce, 2 tbsp. tomato paste, 1 tbsp. fresh lemon zest, 2 tbsp. fresh parsley, 1 tsp. dried oregano, ½ tsp. dried thyme, Sea salt and freshly ground black pepper 
- Stir the ingredients in the pan, then add the chicken thighs. 
- Place in the oven and cook for 20 to 25 minutes, or until chicken is cooked through. 
- Adjust seasoning and serve topped with fresh parsley.