Heat olive oil in a skillet over medium heat.
Sauté onions, garlic, carrots, and celery until soft.
Transfer the sautéed vegetables to the crockpot.
Add chicken breasts and pour chicken broth over them.
Season with thyme, parsley, salt, and pepper.
Cover and cook on low for 6-8 hours or high for 3-4 hours.
Once chicken is cooked, shred it in the pot using two forks.
Stir in the egg noodles and cook for an additional 30 minutes on high.
Taste and adjust seasoning if necessary.
Serve hot, garnished with fresh parsley.