Place chicken breasts in the bottom of the crockpot.
Add chopped onions, carrots, and celery on top of the chicken.
Pour in the chicken broth.
Add minced garlic and dried thyme.
Season with salt and pepper to taste.
Cover and cook on low for 6-8 hours or high for 3-4 hours.
Once cooked, shred the chicken with two forks.
Stir in the egg noodles and cook on high for an additional 30 minutes.
Check seasoning and adjust if necessary.
Serve hot, garnished with fresh parsley.