If using a whole chicken, place it in a large pot or Dutch oven. Cover with cold water. Bring to a boil, then reduce heat and simmer for 1 hour, or until chicken is cooked through. Remove chicken from pot and set aside to cool. Reserve the broth.
If using chicken bones, place them in a large pot or Dutch oven. Cover with cold water. Bring to a boil, then reduce heat and simmer for 2-3 hours to create a rich broth. Strain the broth and discard bones.
Once the chicken is cool enough to handle, shred the meat and discard skin and bones.
In the same pot (or a clean one), heat olive oil over medium heat. Add chopped carrots, celery, and onion. Cook until softened, about 8-10 minutes.
Add minced garlic, thyme, rosemary, and bay leaf. Cook for 1 minute more until fragrant.
Pour in the reserved chicken broth (or homemade bone broth). Add the shredded chicken, salt, and pepper. Bring to a boil, then reduce heat and simmer for 20 minutes to allow flavors to meld.
Add the egg noodles to the pot and cook according to package directions, usually 8-10 minutes, until tender. Do not overcook.
Stir in fresh parsley. Taste and adjust seasoning if needed.
Ladle hot soup into bowls and serve immediately.
Notes
For a richer broth, you can roast the chicken or bones before simmering.
If you prefer noodles that hold their shape well, add them during the last 5 minutes of simmering.
You can add other vegetables like peas or corn during the last 10 minutes of cooking.