Place the chicken breasts at the bottom of the slow cooker. Add the diced onion, sliced carrots, celery, and minced garlic on top of the chicken.

In a medium bowl, whisk together the cream of chicken soup, chicken broth, heavy cream, dried thyme, dried parsley, black pepper, and salt. Pour the mixture over the chicken and vegetables.

Cover and cook on low for 6–7 hours or on high for 3–4 hours, until the chicken is cooked through and tender.

Remove the chicken from the slow cooker and shred it using two forks. Return the shredded chicken to the pot.

Stir in the egg noodles during the last 20–30 minutes of cooking (if cooking on low, increase heat to high). Cover and cook until the noodles are tender but still al dente.

Taste and adjust seasoning if needed. Ladle into bowls and garnish with fresh parsley or grated Parmesan cheese, if desired.