Turn the pot to high pressure/manual and set the timer for 10 minutes. It will take the instant pot about 7-10 minutes to come to pressure before that 10 minutes starts counting down, hence the 20-minute total cook time.
Once the 10 minutes is up and the pot beeps, do a manual release.
Add the butter and milk to the potatoes, then blend them right in the instant pot until they are smooth and creamy.
A great way to add flavor to these potatoes is to add ¼ cup of sour cream when mixing in the milk.
Do not be afraid to mash these potatoes instead of whipping them. That is totally your preference!
If you wish, you can swap the russet potatoes for yukon golds or even red potatoes. Just be sure to have about 3 lbs of them.
No need to drain these potatoes like you would for a stove method. Just another reason why they’re so quick!