In a bowl, stir together the flour, salt & pepper. Place cubed beef in container and toss to coat.
Set Instant Pot to Saute. Place 1 T butter in pot and when melted and foamy add half of the beef cubes. Allow beef to brown, then turn over and brown other side. This should take just a few minutes on each side. Using tongs or a slotted spoon, remove beef cubes and set aside in a bowl/on a plate. Melt remaining butter in Instant Pot and repeat process with the remainder of the beef. Again, remove the browned beef and set aside.
Add onions to Instant Pot and stir. Cook just 2-3 minutes and then add garlic. Stir. Cook 30 seconds. Deglaze the pot with wine (if not using wine, use broth), being sure to scrape up any bits from the bottom of the pot. Stir in worcestershire sauce, thyme, carrot, celery and potatoes. Add the beef on top. Pour in the broth.
Cover the Instant Pot and set vent to "sealing". Use the "stew/meat" function or high pressure, with the timer set to 35 minutes.
When the timer goes off at 35 minutes, allow Instant Pot to naturally release the pressure.
Once pressure is released, carefully remove the cover and stir. If desired, stir in corn.
If a thicker stew is desired, combine 2 T cornstarch with just enough cold water to make it smooth. Pour it into the stew and set back to saute. Continue to cook and stir occasionally until stew has thickened.