Place the chicken breasts at the bottom of the crockpot.
Add the diced onion, carrots, and celery over the chicken.
Pour in the chicken broth, ensuring the chicken is submerged.
Season with garlic powder, thyme, salt, and pepper.
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 heavy cream.
Cover and cook on high for an additional 30 minutes.
Adjust seasoning as necessary before serving.
Serve warm, garnished with fresh herbs if desired.