Heat 1 tablespoon oil in Instant Pot on sauté function. Pat beef dry with paper towels; season with 1 teaspoon salt. Add half of beef in an even layer and cook until browned on all sides, 6–8 minutes. Using a slotted spoon, transfer beef to a bowl. Add remaining tablespoon oil to reserved drippings, repeat browning with remaining beef, cooking 6 minutes. Transfer beef to bowl.
Add onion, garlic and 1 teaspoon kosher salt to drippings; cook 4 minutes.
Stir in carrots, celery, bay leaves, porcini and barley.
Stir in broth, browned beef and any accumulated juices.
Lock lid in place and turn pressure release valve to "sealing". Select high pressure cook function and cook for 25 minutes. Turn off Instant Pot and quick-release pressure. Carefully remove lid, allowing steam to escape away from you.
Using a wide shallow spoon, skip excess grease from surface of stew.
Season with 2 tablespoons lemon juice and fresh dill and parsley. Season with salt to taste.
Top each serving with minced lemon zest.