Instant Pot Mushroom-Barley Stew

In a 6-quart electric multicooker combine the first 13 ingredients (through sage). Lock lid in place; set pressure valve to sealing. Set cooker on high pressure to cook 20 minutes. Let stand to release pressure naturally (about 15 minutes). Carefully release any remaining pressure. Open lid carefully. 2. Season stew with pepper. Top servings with walnuts and parsley.