Score the fat cap of a 3 lb. boneless beef rib roast.
Generously season your roast on all sides with sea salt and ground black pepper. Give it a good coating, even if it seems like too much salt. Trust us, you want to coat it all over!
Place the trivet in the Instant Pot.
Place the roast in the trivet.
Add 1 cup unsalted beef stock and 1/2 cup red wine.
Optional step: Add a few sprigs of fresh herbs to the Instant Pot, such as rosemary, thyme, or parsley (whichever you prefer).
Lock the lid in place and make sure the vent is in the “sealing” position. Choose the manual setting, low pressure, and set the timer for 5 minutes.
Once the 5 minutes is done, do not remove the lid or release the pressure. Leave the roast in the pot for 30 more minutes. The Instant Pot will automatically switch modes to the “keep warm” setting.
Once 30 minutes are up, open the pot and insert a meat thermometer at the thickest part of the rib. As always, be careful when removing the lid.The meat thermometer should read approximately 115°F. If the temperature is too low, put the lid back on and leave it on warm for 5 to 10 minutes longer, then check again. When searing, the temperature will rise, so you want to pull the prime rib out of the pot early (before it cooks to your desired temperature).
Remove the roast to a plate. Strain the liquids from the Instant Pot into a cup, and set aside.
Remove the trivet from the Instant Pot. Select the highest saute setting. Add 3 Tbsp. vegetable oil to the pot. Place the prime rib roast back and sear it until it browns on all sides, approximately 10-15 minutes. The prime rib should have a nice crust on it. If you prefer, you can brown the roast in a cast-iron skillet on the stovetop. This is a method for reverse searing prime rib, which locks in flavor and ensures a perfectly cooked cut of beef versus searing it at the start.
Insert the meat thermometer into the thickest part of the prime rib and make sure you cook it to your desired degree of doneness. For checking prime rib temp, see the chart above. For quick reference, the temperature for medium-rare prime rib is 135 °F and 145 for medium.
Remove the roast to a platter, tent with foil, and let it rest for 15 minutes.
Add the strained liquids back to the pot, then add 3 Tbsp. all-purpose flour and stir to make a gravy.