The other night I accidentally pulled a beef roast out of the freezer thinking it was a pork roast, but made dinner with it anyway after my son said "go for it". Coated the roast (about 1 1/2#) with salt and granulated garlic, and browned it in some butter with the instant pot on saute. Then deglazed the pot with some water, threw in some potatoes cut into thirds (home grown yukon gold and purple potatoes). Placed the roast on top, fat side up. Topped with about a cup of homemade sauerkraut. Cooked under pressure for 30 minutes, followed with a natural release. Removed the roast and potatoes from the pot, added a little cornstarch to the liquid to thicken, and put back on saute.
The recipe I got had you mashing the potatoes, but I don't bother doing that and just leave them like I would for pot roast.
It was good, but I'd like to try again with the "proper" pork loin roast.