Sauté the veggies and garlic. Turn your Instant Pot to “Sauté” mode (normal heat). Add a splash of oil or broth. Toss in the onions, carrots, celery, and garlic. Cook for 3–4 minutes, stirring often, until the onions turn translucent.
Cook the chicken. Add the chicken breasts or thighs to the pot, followed by thyme, parsley, salt, pepper, and all the broth. Stir gently. Place the lid on, set the valve to “Sealing,” and cook on high pressure for 10 minutes. When the timer goes off, let the pressure release naturally for 5 minutes, then do a quick release. Transfer the chicken to a plate and shred it with forks.
Thicken the broth. Turn the Instant Pot back to “Sauté” mode. Stir in the cream of chicken soup until smooth. Mix the cornstarch and water in a small bowl to make a slurry, then pour it into the pot. Simmer for 2–3 minutes until the broth thickens slightly.
Add the dumplings. Tear the biscuit dough into small pieces and drop them into the broth one at a time. Gently press them down with a spoon so they’re mostly submerged. Add frozen peas here if using. Place the lid back on, set it to “Sealing,” and cook on high pressure for 5 minutes. Quick-release the pressure immediately.
Serve and enjoy! Stir everything gently to mix the shredded chicken back in. Ladle into bowls and sprinkle with fresh parsley if desired.