Place onion, garlic and oil into the instant pot and sautee it for 3-5 minutes or until onions are tender. Stir in mushrooms, carrots, barley, broth and salt. Mix well.
Place the lid onto the instant pot and close the pressure release valve. Set instant pot to manual, high pressure for 18 minutes. When cooking cycle is complete, let pressure cooker sit for 10 minutes and then quickly release the pressure valve and open the pot.
Stir in fresh kale for 2 minutes or until heated through and wilted.