First, slice up your potatoes and put the vegetable broth in the Instant Pot.
Put the potatoes into the Instant Pot and cook on "Manual" high pressure for 1 minute.
Quick release the pressure, then preheat your oven to the Broil setting.
Put the potatoes from the Instant Pot into an oven-safe dish, but leave the liquid in the Instant Pot.
Add the rest of the ingredients into the Instant Pot, and then cook on "Saute" until all is mixed and smooth.
Now, put this cheesy mixture on top of your potatoes, which are in the other oven-safe dish.
Add in the rest of the cheese if you have left overs, and then broil the scalloped potatoes in the oven for about 5 mintues.
Once done, get out of the oven and serve.