Turn the pressure cooker to saute. Once hot, add in the oil. Sear meat on all sides, 3-4 minutes per side. Remove meat from inner pot.
Pour in beef broth and scrape up any browned bits on bottom of instant pot.
Add roast back into the pressure cooker, along with the onion powder, garlic, and horseradish.
Cook on high pressure for 20 minutes per pound.
When the cook time has elapsed, allow for pressure to release for 10-20 minutes.
For Frozen Pot Roast
Place roast, beef broth, salt, pepper, onion powder, garlic, and horseradish in the inner pot of pressure cooker.
Cook on high pressure for 30 minutes per pound.
When cook time has elapsed, allow for pressure to release for 10-20 minutes.
Pot Roast with Carrots and Potatoes
Sear roast as directed, if desired.
Add beef broth, salt, pepper, onion powder, garlic, and horseradish into the pressure cooker and cook for 20 minutes LESS than directions state (Cook for 40 minutes on high pressure for FRESH 3 pound Pot Roast or 70 minutes on high pressure for FROZEN 3 pound roast).
Once cook time has elapsed, allow the pressure to release naturally for 10 minutes.
Open the instant pot and add in carrots and potatoes, seal pressure cooker and cook on high pressure for 20 minutes, or for 10 minutes for less tender vegetables.
Allow the pressure cooker to naturally release pressure for 10-20 minutes before releasing any remaining pressure. Serve the pot roast.
Store leftovers in the refrigerator for up to 3 days. It is NOT necessary to sear the pot roast before cooking, but I do find it helps to add texture and flavor. Directions for Gravy:
Strain the leftover broth out of the inner pot.
Turn the Instant Pot to saute and add in 2 tablespoons of butter.
Whisk in 2 tablespoons of flour once the butter has melted and then let cook for 1 minute.
Slowly whisk in 2-3 cups of the leftover cooking liquid, whisking well.
Let bubble and thicken for several minutes.
Alternatively, you can remove the roast, potatoes, and carrots and then turn the instant pot to saute and let the leftover broth come to a boil. Whisk together ¼ cup cornstarch with ¼ cup water and then whisk into the liquid and let thicken.
Notes on Cooking Time for Potatoes and Carrots: If you want your vegetables less soft, cook for only 10 minutes, not 20 minutes.