In a colander, run cold water and scrub off—as best you can—the starchy surface with your thumbs.
Toss these into a pot of cold water, enough to submerge the potatoes with an extra inch of water.
Turn the heat to high and bring to a boil. Boil for 30 minutes (knife should slide in with no resistance).
In the mean time, take 1 1/2 sticks of butter from the fridge and cube them. Place butter into a bowl and back into the fridge.
In a separate sauce pot, warm heavy cream over very low heat.
Drain potatoes and press through a ricer back into the waterless-but-still-hot pot.
Add the chilled cube butter in three batches, whipping the potatoes with a large metal spoon vigorously.
Sprinkle in salt and pepper to taste.
Slowly pour in the warmed cream, and keep whipping with the spoon. You may choose not to add the full cup of cream, but I like my potatoes ethereally fluffy.
Sprinkle on fresh chives, add gravy if you desire (see recipe below), and serve immediately.