You first will need to peel your potatoes, and then add them into the Instant Pot.
You want to use only enough water to cover the potatoes. Season lightly with some salt.
Cover the Instant Pot and then cook for 10 minutes on high. You can use the quick release function to check the potatoes.
The potatoes are done when you are able to insert a knife into them easily.
Drain most of the water, but leave about 1/2 cup out on your counter in case you are serving your potatoes later on.
Put in your sour cream, buttermilk, black pepper, salt, and butter.
Mash these potatoes up with a potato masher. Adjust your salt and pepper accordingly, sometimes you might need a little more.
You can add parsley or chopped chives as an optional garnish.