Heat 2 tablespoons of olive oil in the Instant Pot set to the Sauté function. Add the beef chuck roast and cook until browned on all sides, approximately 4-5 minutes per side. Pour in the beef broth.

In a plastic bag, combine the baby potatoes, baby carrots, quartered onion, dry onion soup mix, and the remaining 2 tablespoons of olive oil. Seal the bag and shake to evenly coat the vegetables.

Transfer the vegetable mixture from the bag to the Instant Pot, spreading them evenly around the beef chuck roast.

Close and lock the Instant Pot lid. Set the cooker to High Pressure using the program instructions, with a timer of 60 minutes. Allow for 10-15 minutes of pressure buildup.

Perform a quick release of the pressure according to manufacturer-specific instructions (~5 minutes). Carefully remove the lid once safe and transfer the beef and vegetables to a serving platter, leaving the broth and drippings in the pot.

To make the gravy, select the Sauté function, bringing the liquid in the Instant Pot to a boil. Mix water and cornstarch in a bowl, then pour the mixture into the boiling broth, stirring frequently until slightly thickened (2-3 minutes). Season the gravy with garlic salt and black pepper.