Turn a 6-quart or 8-quart Instant Pot on and press the Saute button.
Add the sliced carrots, celery, diced onion, minced garlic and butter. Sauté until the onions are soft, about 3 minutes. Turn the sauté setting off.
Add the salt, pepper and dried parsley. Toss to coat the vegetables.
Add the whole chicken pieces to the Instant Pot. Add the bay leaves and fresh or dried thyme.
Pour 6 cups of the the chicken broth over the ingredients. Stir with a wooden spoon.
Place the lid on the Instant Pot. Make sure the valve is set to the sealing position. Press the manual button and set the pressure cooking time to 7 minutes.
After the timer beeps alerting you that the pressure cooking has finished allow the steam to release naturally for 15 minutes. Then push the valve to the releasing position and wait for all of the steam to escape and the pin to drop.
Carefully twist the lid off away from your face. Remove the bundle of fresh thyme if used to season the chicken soup.
Use a slotted spoon or a kitchen tong to remove the hot cooked chicken from the pot and place it in a bowl. Allow the chicken to rest for about 5 minutes before shredding the chicken with two forks.
Return the shredded chicken to the inner pot of the Instant Pot.
Pour the instant rice into the Instant Pot and stir with a wooden spoon. Place the lid on the Instant Pot and lock into place. Allow the rice to cook in the hot chicken broth until tender, about 15 or 20 minutes. See Notes.
Remove the lid once again and stir the cooked rice into the chicken soup. If the rice has absorbed too much of the chicken broth add the remaining 2 cup and stir.
Makes 8 servings.