In a large slow cooker, add chicken breasts, onion, carrots, celery, garlic, bay leaves, peppercorns, salt, pepper and chicken broth.
Cover and cook on Low for 8 hours or on High for 4 hours.
After remove chicken breasts on a large plate and set aside. Discard bay leaves, peppercorns and onion.
Add egg noodles, stir, cover and cook on High for 20 minutes or until pasta is ready. Shred chicken breasts and return to slow cooker along with parsley.
Stir, taste and adjust any seasonings to taste. Serve hot.
Notes
Store: Store slow cooker chicken noodle soup leftovers in an airtight container for up to 3 days. If you need it to last for a few days I recommend to cook pasta separately. Then heat up the soup and add noodles to each individual bowl right before serving.
Freeze: I would recommend to freeze it without the pasta. Cooked pasta doesn't taste good thawed. If you plan on freezing this soup, just don't add pasta at the end. You can freeze chicken noodle soup in any airtight container for up to 3 months.
Reheat: I usually warm up cold or defrosted soup on the stove by simmering desired amount in a small pot on low heat for about 5-10 minutes. That's it.