Turn Instant Pot to Saute mode and heat oil. Add poblano, onion and jalapeno. Mix well. Cook covered with glass lid for 4-5 mins until the onions turn translucent.
Mix arrowroot powder or corn starch slurry in the soup and turn Instant Pot to Saute mode. Bring the chowder to a gentle boil. Garnish with fresh parsley. Enjoy hot with a sprinkle of cayenne pepper for additional heat.