1. Set the Instant Pot to sauté mode. Add a bit of oil and cook the chicken pieces until browned.
2. Add the carrots, celery, frozen peas, chicken broth, salt, pepper, and thyme. Stir well.
3. Close the lid and set the Instant Pot to high pressure for 10 minutes.
4. While the chicken is cooking, prepare the dumplings. In a bowl, mix flour, baking powder, and salt. Add milk and melted butter, stirring until just combined.
5. Once the cooking time is up, perform a quick release. Open the lid and set the Instant Pot back to sauté mode.
6. Drop spoonfuls of the dumpling batter into the pot. Cover with a glass lid and let the dumplings cook for about 5-7 minutes, until they are cooked through.
7. Stir in the heavy cream and adjust seasoning if needed. Serve hot.