Preheat you Instant Pot using the Saute function on the display panel.
Melt butter, then add onion, carrot, and celery. Season with ½ teaspoon salt and ¼ teaspoon pepper, and allow to cook 4 to 5 minutes until vegetables are tender.
Add garlic and cook until fragrant, about 30 seconds. Press Cancel, then add chicken, potatoes, broth, seasoning, bay leaf, and remaining salt and pepper.
Stir well, then secure lid and pressure valve. Cook on Manual High for 10 minutes, allowing a 10 minute natural release before releasing the rest via pressure valve.
Combine cornstarch and water and stir until dissolved, then remove Instant Pot lid. Press Saute, stir in cornstarch slurry, and simmer for 4 to 5 minutes until thickened. Add fresh chopped parsley, tasting and seasoning as desired. Remove the bay leaves and serve hot.
Chicken: You can use boneless chicken thighs instead of breasts, if desired.
Vegetables: You can substitute green beans or sweet potatoes, if desired.
Italian Seasoning: If you don't have Italian seasoning, you can use 1/4 teaspoon each of rosemary, basil, thyme and oregano.
Cornstarch: Use arrowroot instead, if needed.
How to Store: Store any leftovers in an airtight container in the refrigerator for up to 3-4 days.Freezing: This chicken stew freezes exceptionally well. Transfer the soup to a freezer-safe bag or container and freeze for up to 6 months.Reheating: Reheat from the fridge using a saucepan on the stove top or in the microwave. If frozen, thaw overnight and reheat in the microwave or on the stovetop before serving.