Bring a large pot of lightly salted water to a boil. Add egg noodles and oil, and boil for 8 minutes, or until tender. Drain, and rinse under cool running water.
In a large saucepan or Dutch oven, combine broth, salt, and poultry seasoning. Bring to a boil. Stir in celery and onion. Reduce heat, cover, and simmer 15 minutes.
In a small bowl, mix cornstarch and water together until cornstarch is completely dissolved. Gradually add to soup, stirring constantly. Stir in noodles and chicken, and heat through.