Add oil, carrots, celery, onion, salt and pepper. Cook, stirring frequently, until onions are translucent.
Add broth, water, chicken, thyme, bay leaf, and rosemary. Secure lid and turn valve to "seal." Set Instant Pot on Manual for 11 minutes. Quick release pressure when done cooking. Remove chicken to a plate, and remove and discard bay leaf and rosemary sprig.
Turn Instant Pot back to Sauté. When soup comes to a boil, add noodles and continue to cook, stirring occasionally, until noodles are tender, or about 7-8 minutes (check the package for exact cooking time).
Meanwhile, shred chicken with two forks and return to pot when shredded.
When noodles have finished cooking, add peas and parsley and stir to combine. Taste and adjust seasoning for salt and pepper. You may also add more chicken broth or water if it's thicker than you like it.
This recipe would also work well with whole wheat pasta.