Place whole chicken, carrots, celery, onion, garlic, bay leaves, whole peppercorns, parsley stems, dried thyme, and cold water in a very large pot. Bring to a boil, skim foam at the start, then reduce heat to a gentle simmer.

Simmer for 1.5 hours, keeping the broth at a steady low bubble until the chicken is very tender. Look for the broth to turn darkly golden and the meat to pull easily.

Strain the broth and discard the used vegetables. Remove all meat from the chicken and shred into bite-size pieces.

Return the clear broth to the pot, then taste and season with salt. Keep the heat medium so the broth is ready for the next simmer.

Bring the seasoned broth to a simmer, then add sliced carrots, celery, and diced onion. Ensure the vegetables are fully submerged and the surface shows small bubbles.

Cook for 10 minutes, until the vegetables are tender. You should be able to pierce the carrot and celery pieces with a fork.

Add wide egg noodles and cook for 6-8 minutes. Watch for the noodles to soften and the broth to lightly thicken.

Stir in shredded chicken and fresh parsley, then cook just until warmed through. The chicken should steam hot and the parsley should look bright green.

Adjust seasoning with salt and pepper to taste. Serve hot with an even distribution of broth, noodles, chicken, and vegetables.