Take beef out of the refrigerator, season with salt, pepper and garlic powder. Optional: Let stew meat come to room temperature before cooking, this will create more tender beef.
Set the instant pot to sauté, heat one tablespoon of oil and add half of the stew meat making sure not to crowd the meat. Sear both sides of the meat, about 3 minutes on each side, remove the stew meat to a plate. Add the remaining 1 tablespoon of oil and repeat with the second batch. Remove all meat from the instant pot and set aside. Add 1/2 cup of broth to the pot and use a wooden spoon to scrape up any bits of beef and to deglaze the bottom of the instant pot. This is an important step. If any pieces of meat are left stuck to the bottom of the instant pot, you can get the dreaded burn message while cooking.
Add the stew meat back, potatoes, carrots, onion, celery, garlic, Italian seasoning, Worcestershire sauce, 3 cups of broth and wine to the instant pot. Stir until well combined.
Lock the lid on the instant pot, set the valve to seal. Set the cook time for 30 minutes on high pressure. (Keep in mind it will take about 10 minutes to come to pressure.
Let the instant pot natural release the pressure for 10-15 minutes. This means do not open the instant pot once it finishes the cooking time countdown. Leave the instant pot completely sealed and closed and let the pressure naturally release.
While the pot is natural releasing make the slurry. To make the slurry, whisk to combine 4 tablespoons cornstarch with the remaining 4 tablespoons broth in a small bowl.
Quick release any remaining pressure, turn the instant pot on to sauté, and pour in the slurry and stir to blend. Continue to sauté, stirring often, until the gravy has thickened, about 2 to 3 minutes. Serve warm with a hunk of bread and a little fresh parsley on top, if desired.