Heat the oil in a 6-quart saucepot over medium heat. Add the onions, carrots, parsnips and celery. Cook for 5 minutes or until the vegetables are tender. Add the broth and heat to a boil. Reduce the heat to medium-low and cook for 30 minutes or until the vegetables are very tender.
Stir in the chicken, peas and parsley and heat through. Season to taste. Divide the soup mixture among 8 serving bowls.
