In a large pot, bring the chicken broth to a simmer over medium-high heat. Add the chicken breasts to the pot and bring the broth back to a simmer.
Reduce the heat to medium-low and cover the pot. Simmer the chicken until cooked through, about 10-15 minutes.
Remove the chicken breasts from the pot and set them aside to cool. Add the onion, carrots, celery, garlic, thyme, parsley, salt, and pepper to the pot.
Increase the heat to medium-high and bring the broth to a simmer. Reduce the heat to medium-low and cover the pot.
Simmer the vegetables for about 10-15 minutes, or until they are tender. While the vegetables are simmering, shred the cooled chicken breasts with two forks.
Add the egg noodles to the pot and cook for an additional 5-7 minutes, or until the noodles are tender.
Stir in the shredded chicken and cook for another 2-3 minutes. Taste and adjust the seasoning as needed.
Serve hot, with additional parsley or thyme for garnish, if desired. To make a richer broth, you can add a tablespoon of butter or olive oil to the pot when sautéing the vegetables.
For added flavor, you can use chicken thighs instead of chicken breasts. You can also add a bay leaf or a few peppercorns to the pot while simmering the broth for added depth of flavor.
To make a creamier soup, you can add a cup of heavy cream or a tablespoon of flour mixed with a little cold water to the pot before adding the noodles.