Using a 6qt or larger Instant Pot, select Saute mode and High.
Once it reads HOT, add the butter and melt. Add diced onion and cook for 1 minute. Add garlic, stir and cook for 1 minute, until fragrant.
Add the rest of the veggies, carrots, and celery. Stir and cook for 5-7 minutes, until the veggies are just tender.
Add the basil, dried parsley, and pepper flakes. Add salt and pepper.
Add chicken and pour the broth on top, don't go over the max line. Tie together with kitchen twine thyme and rosemary and add to the pot. Add bay leaves.
Cover and secure the lid, point the valve to seal. Cook on High Pressure for 10 minutes. This is followed by a 10-minute Natural Pressure Release. Release manually any remaining pressure.
Take off the lid and select Saute on medium heat. Remove the chicken and add it to a plate. Next, use two forks to shred it.
Remove and discard bay leaves, thyme, and rosemary.
Add the dry noodles to the soup, simmer uncovered for another 7-10 minutes, or until noodles are cooked.
Taste and adjust for salt and pepper.
Serve garnished with fresh chopped parsley.