Pat the pork tenderloins dry with paper towels. Sprinkle salt and pepper all over the pork tenderloins.
Heat an Instant Pot using the Sauté function.
Add the oil and heat, making sure to stir it around to coat the inside so that the pork doesn't stick.
Place the tenderloins into the post in a single layer, curving them in the pot if needed and fry them until they are nicely browned on the bottom, around 4 minutes.
Flip the tenderloins over and brown on the other side, around 4 minutes.
Once they are done, transfer the tenderloins to a plate.
Add more oil if needed and then add in the onions. Fry the onions until they are softened and translucent.
Add in the garlic and fry until fragrant, another 1-2 minutes. Add in the rosemary and sage and heat until fragrant, around 30 seconds.
Deglaze the bottom of the Instant Pot with a little of the white wine, scraping up any browned bits at the bottom of the pot with a wooden spoon.
Add the remaining wine and the chicken broth to the bottom of the pot.
Place the tenderloins in the broth.
Lock on the lid and set the pressure valve to seal. Program to cook for 1 minute under high pressure.
Let the pot naturally release, around 15 minutes.
Open the Instant Pot according to the manufacturer's instructions and check the pork’s temperature in the thickest part of the meat, with an instant read probe thermometer. Pork can now be cooked to a minimum internal temperature of 145 °F.
If the temperature isn't quite there, place the lid back on, lock the lid back in place and continue to cook in the residual heat for a few more minutes.
Place the tenderloins onto a cutting board to rest.
Turn the pressure cooker back on to Sauté and whisk in the heavy cream. Simmer until thickened, about 2 minutes.
Slice the pork into medallions and serve with the gravy.
We only need to cook this for one minute as it takes a solid 8-10 minutes of heating time for the Instant Pot to heat up.
Residual heat in the pressure cooker is your cooking friend or enemy. Remember that the roast will keep cooking in the Instant Pot after the pressure release - great if the roast isn't done yet, but can overcook the roast.