Begin by preparing your ingredients: dice the chicken into 1-inch chunks, thinly slice the carrots, chop the celery finely, and finely dice the onion. Measure out your noodles and broth, so everything is ready to go.
Add the diced chicken to the slow cooker, spreading it evenly across the bottom. Layer the sliced carrots, chopped celery, and diced onion on top. Pour in the chicken broth, ensuring all ingredients are submerged but not overfilled. Tuck in the bay leaf and sprinkle with salt and pepper.
Cover the slow cooker with its lid and set it to low. Let it cook for about 6 hours, during which the chicken becomes tender and the flavors meld into a fragrant, smoky broth. The house will fill with a warm, savory aroma.
Once the cooking time is up, remove the lid and check that the chicken is tender enough to shred easily. The vegetables should be soft and fragrant, and the broth rich and layered.
Bring a pot of water to a boil separately, then add the egg noodles. Cook until just al dente according to package instructions, usually about 7 minutes. Drain and set aside.
Remove the bay leaf from the slow cooker. Stir in the cooked noodles, then cover and cook on high for another 15-20 minutes, allowing the noodles to soak up some of the flavorful broth and become chewy and satisfyingly bouncy.
Taste the soup and adjust seasoning with more salt and pepper if needed. Ladle the hot, fragrant soup into bowls, garnish with chopped parsley, and enjoy the comforting blend of tender chicken, soft vegetables, and hearty noodles in a smoky, savory broth.
