Place the chicken breasts into the crockpot and pour in the chicken broth, ensuring they are mostly submerged. Add sliced carrots, diced onions, celery if using, dried thyme, and a pinch of salt and pepper. Cover with the lid and set the crockpot to low.
Let the mixture cook for 6-8 hours until the chicken is tender and easily shredded, and the vegetables are soft. The house will fill with a warm, savory aroma as it simmers.
Carefully remove the chicken from the crockpot and shred it with two forks until it’s pulled into bite-sized pieces. Return the shredded chicken to the broth and stir to combine.
Increase the crockpot temperature to high and add the uncooked wide egg noodles directly into the hot broth. Cover and cook for 8-10 minutes, stirring occasionally, until the noodles are tender but still slightly chewy.
Taste the soup and adjust the seasoning with additional salt and pepper if needed. Stir in chopped fresh parsley for a bright, fresh flavor and aroma.
Serve the hot, hearty soup in bowls, garnished with extra parsley if desired. Let it sit for a few minutes so the flavors meld before enjoying that cozy, comforting meal.