Turn the pressure cooker to saute, add the oil and let heat.
Season the roast with salt and pepper liberally on both sides. Once seasoned, add the roast to the heated oil and sear the meat on all sides, 3-4 minutes per side. Once the meat is browned, remove it from the inner pot. And turn the Instant Pot off.
Pour in about ½ cup of the beef broth and scrape up any browned bits on the bottom of the inner pot. This will prevent a burn notice from happening--so don't skip this step.
Add roast back into the pressure cooker, along with the remaining beef broth. Sprinkle with onion powder and a pinch of salt and pepper. Top the roast with minced garlic and horseradish.
Place the lid on the pressure cooker. Cook on high pressure for 20 minutes per pound.
When the cook time has elapsed, allow for pressure to release for 10-20 minutes. This is really important, as it keeps the roast tender and juicy.
Once the pressure has been released, open the inner pot and remove the roast, and place it on a cutting board or platter. Tent with foil and let rest for 10-15 minutes before cutting.
If cooking carrots and potatoes, add them now to the liquid inside the inner pot. Close the lid and cook on high pressure for 10 minutes or 20 minutes for really soft potatoes and carrots.
Once the cooking time has elapsed, let the pressure release for 5 minutes and then do a quick release of pressure.
Serve the potatoes, carrots, and roast with the cooking liquid.
Frozen Pot Roast Directions
For a frozen pot roast, skip searing the roast. Instead, pour the beef broth into the inner pot and stir in the salt, pepper, and onion powder. Add the frozen roast to the inner pot and top with garlic and horseradish. Cook on high pressure for 30 minutes per pound with a 10-20 minute natural pressure release. Cook potatoes and carrots as the instructions above state.
Leftovers: Store leftovers in a sealed container with the cooking liquid in the refrigerator for up to 3 days. Searing the Roast: It is NOT necessary to sear the pot roast before cooking, but I do find it helps to add texture and flavor. Horseradish: Use prepared horseradish, not horseradish sauce. Notes on Cooking Time for Potatoes and Carrots: If you want your vegetables really soft, cook for only 20 minutes. Directions for Gravy:
After the roast and vegetables are cooked, strain the cooking liquid from the inner pot and then return the inner pot to the instant 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 1-2 cups of the leftover cooking liquid, whisking well.
Let bubble and thicken for several minutes, whisking constantly.
Gluten-Free Gravy: Alternatively, after the roast and vegetables are cooked, strain the cooking liquid from the inner pot and then return the inner pot to the instant pot. Add 2 cups of the strained liquid back to the inner pot and turn the Instant Pot to saute. Let the mixture come to a bubble. Whisk together ¼ cup cornstarch with ¼ cup water until dissolved, and then whisk that mixture into the heated broth. Whisk constantly and let cook until thickened.