Season all sides of the roast with the salt, pepper, garlic powder, and onion powder. Put oil in the Ninja Foodi pot. Place seasoned roast in the pot and SAUTE on HIGH, browning all sides. (then take meat out, add some of your broth and deglaze - scrape stuck on bits off bottom off, then put meat back in)
Add beef broth and onions to the pot. Close lid and set on high pressure for 60 minutes. Allow pressure to naturally release for 10 minutes, then quick release.
Remove roast and onions. In a small bowl, combine cold water and cornstarch. Turn Ninja Foodi to saute. When the juice begins to boil, slowly stir in this mix.
Cook until gravy forms. Depending on the consistency, you may have to add more cornstarch/water slurry.