Add chicken and 1 cup of stock to the pressure cooker. Cook, using manual high pressure for 14 minutes (only 9 minutes for thawed chicken).
While the chicken is cooking, dice the carrots and celery. Chop the parsley.
Perform a quick release of the pressure in the Instant Pot. When the pressure has subsided, open the lid and remove the chicken to a plate to cool slightly.
Add 6 cups of stock, the diced celery and carrots, salt, pepper, poultry seasoning, and pasta to the insert of the pressure cooker. Stir to mix things together well.
Cook, using manual high pressure, for 6 minutes. While the soup is cooking, shred or dice the chicken.
Once the pasta has cooked, perform a quick release of the pressure. Add shredded chicken and the parsley to the soup, stir together, and serve.
Nutrition facts are sometimes provided below and are calculated using an online calculator. With specific brands of ingredients and additions, omissions, or substitutions the nutrition facts may change. We encourage you to use your own nutrition facts calculator to obtain the most accurate nutrition facts for your meal.