Heat oil in a large skillet, season chicken with salt and pepper and cook in oil for five minutes. Turn the chicken, and cook for another 5 minutes. Remove from the skillet and reserve.
Add onions, carrots and garlic to the skillet, cover and cook over low heat until the vegetables are tender, about 25 minutes. Uncover the skillet and add the chicken stock, orange juice, tomatoes and rosemary. Season with salt and pepper and simmer for about 15 minutes. Return the chicken to the pan and simmer for 20 to 30 minutes until the chicken is tender, mixing and basting occasionally. Add the red pepper and zucchini and cook for another 15 minutes or so until the vegetables are tender and the chicken is cooked through. Sprinkle with the parsley and serve with steamed new potatoes or crusty bread