In a heavy-bottomed pot, heat the olive oil over medium high heat. Add chicken thighs and sear until brown, about 3 minutes on each side. Transfer to a chopping board and cut the thighs into halves. Set aside.
To the same pot, still over medium heat, add the onion and garlic and cook until translucent and soft, about 3 minutes. Season with salt, add the thyme and rosemary, and cook until fragrant, about 2 minutes. Add the carrots and celery and cook until translucent, about 8 minutes.
Add the flour and cook, stirring constantly, for 3 minutes, until all the vegetables are coated and the raw taste has cooked off. Slowly pour in the chicken stock, stirring to break up any lumps of flour.
Add the chicken potatoes, and pepper. Bring to a boil, then reduce the heat. Simmer for 20 minutes until the chicken and potatoes are fully cooked and the liquid has slightly thickened. Taste and adjust the seasoning if needed. Discard thyme and rosemary sprigs.
Ladle into bowls, garnish with parsley, and serve immediately.