Best chicken noodle soup recipe - Grandma's recipe

Grandma's Chicken Noodle Soup & the best
INGREDIENTS
2 1/2 cups wide egg noodles
1 teaspoon vegetable oil
12 cups chicken broth
1 1/2 tablespoons salt
1 teaspoon poultry seasoning
1 cup chopped celery
1 cup chopped onion
1/3 cup cornstarch
1/4 cup water
3 cups diced, cooked chicken meat
DIRECTIONS
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.