Turn the Instant Pot onto Saute MORE (or HIGH depending on your Instant Pot). Wait until the display reads HOT.
While waiting for the Instant Pot to preheat, season all sides of the roast with salt and pepper, if desired.
When the display reads HOT, add the butter. Proceed to brown each side of the roast. You'll know it is time to flip when the roast no longer sticks to the bottom of the pot.
Remove the browned roast and set aside.
Pour the broth into the pot and scrape the bottom until it is clean.
Add the crushed tomatoes, onion mix, au jus mix, Worcestershire sauce and parsley to the pot. Add the roast back into the pot.
Cook on Manual HIGH for 100 minutes with a 15 minute NPR before manually releasing the pressure.
While the Instant Pot is naturally releasing it's pressure, wash and prep the veggies. I like to cut the potatoes in half, and then cut each half into four pieces. Place in your steamer basket.
After the roast is finished, carefully remove the roast and place on a plate, cover with foil and rest.
Place the steamer basket into the Instant Pot and cook on Manual HIGH for 4 minutes, quick release the pressure.
Remove the veggies. Turn the Instant Pot onto Saute.
Thicken the gravy with a corn starch slurry until it has reached your desired thickness.
Roughly break up the meat, serve alongside the veggies with gravy drizzled on top.