Turn Instant Pot to the 'saute' setting. Add the 2 tablespoons of olive oil and allow it to heat.
While the olive oil is heating, rub the salt and pepper all over the roast, making sure to get all sides.
With the pan and olive oil heated, add the roast to the bottom of the pan and sear each side for 3-5 minutes.
To a small bowl, combine the beef broth/stock, minced garlic, Italian seasoning, and Worcestershire sauce. Whisk to combine.
ADDING VEGETABLES: You can add the vegetables with the roast, but they will be on the softer side when the roast is done. Adding them to the broth mixture with the roast will help to add flavor to the broth and dish as they cook down. If you prefer more firm carrots and potatoes - add them at the end with some additional time attached.
Once you've seared the second side of the roast - cancel the 'saute' setting. Pour the broth mixture over the roast, place the lid on, lock it, and make sure the vent is set to the 'sealed' position. *As noted in the instruction above, you can add the vegetables now or wait.
Turn it to the 'pressure cook' setting, on high, and set the timer for 60 minutes. If using a larger roast, increase your time by 10 minutes per pound.
When the timer goes off: *IF YOU ADDED THE VEGGIES WITH THE ROAST: Do not do a quick release. Do a 10-minute natural release followed by a quick release. *IF NO VEGGIES: do a quick release to remove any pressure from the pot. Once all pressure is released, remove the lid. Check the roast. If it is fork tender (to your preference), then remove it now and cover with foil to keep warm. If not, leave it in for the next step to allow it to cook even more. Add the potatoes, onions, and carrots. Put the lid back on, and turn the valve back to the 'sealed' position. Select the 'pressure cook' setting and set the timer for 10-15 minutes. Time will be dependent on how large your potatoes are cut, as well as how firm you like your vegetables.
When the timer goes off, allow for a 10-minute natural release, before doing a quick release for any additional pressure prior to removing the lid.
Remove the vegetables and beef to a serving bowl and cover with foil to keep warm. If the broth has any leftover chunks from the meat or vegetables, use a skimming spoon to filter the broth. Safely taste test the beef broth and add any additional salt and pepper, to taste. If you're using regular beef broth or stock, you may want to skip adding more salt.
Gravy: Turn the Instant Pot to the 'saute' setting on high. Combine the cornstarch with the water, whisk to fully mix. Allow the broth to come to a slight boil, then whisk in half of the cornstarch mixture. Whisk to thoroughly combine with the broth, allowing it to thicken as you whisk. If desired, add the second half of the cornstarch mixture to reach desired thickness. Depending on how thick you like your gravy, you may need to add more cornstarch.
Serve gravy with pot roast. Garnish with freshly chopped parsley or thyme (optional).