Combine the salt, pepper, garlic powder, and onion powder in a small bowl. Season the chuck roast on all sides with all of the seasoning mixture.
Using the Instant Pot SAUTE function at its highest heat setting, heat the olive oil until the Instant Pot reads HOT. Add the chuck roast and sear on both sides until very nicely browned, about 4 minutes per side.
Remove the roast from the Instant Pot to a plate.
Add the beef broth to the Instant Pot. Using a wooden spoon, scrape up all of the browned bits from the bottom of the pot.
Return the roast to the Instant Pot. Put the lid on, make sure the steam release valve is set to SEALING, and cook on HIGH pressure for 45 minutes. Note: It will take the Instant Pot about 10 minutes to come to pressure before the cooking time begins to count down. When the cooking time has finished, immediately and carefully quick-release the pressure.
Add the carrots and potatoes to the Instant Pot. Press the vegetables down into the broth as best as you can (it's okay if they are not all covered). Put the lid on, make sure the steam release valve is set to SEALING, and cook on HIGH pressure for 5 minutes. Note: It will take the Instant Pot about 10 minutes to come to pressure before the cooking time begins to count down. When the cooking time has finished, turn off the Instant Pot and allow the pressure to naturally release for 20 minutes, then quick-release any remaining pressure.
Remove the meat, carrots, and potatoes to a serving dish. Using two forks, shred the meat. Cover with foil and keep warm.
Using the SAUTE function of the Instant Pot, bring the broth to a boil.
In a small bowl, combine the cornstarch and cold water to make a slurry. While constantly stirring the broth, add the slurry. Cook, stirring occasionally, for 2 to 3 minutes or until the gravy has thickened slightly. Note: I don't make a super-thick gravy. If you would like your gravy thicker, just add more cornstarch slurry.
Serve the pot roast, carrots and potatoes with the gravy and ENJOY!