Peel the potatoes. Cut into chunks (quarters, if they’re small).
Add the potatoes to the Instant Pot. Add 1 tablespoon of the salt and the water. Lock the lid. Place the pressure release handle (vent) in the “Sealing” position.
Cook on High Pressure for 12 minutes: Press the Pressure Cook button, making sure the “High Pressure” setting is selected, and set the time. Note that it takes about 15 to 20 minutes for the pot to “preheat” and come up to pressure before it starts cooking. (During cooking, avoid touching the metal part of the lid.)
Quick release: Vent the remaining steam from the Instant Pot by moving the pressure release handle to “Venting”, covering your hand with a towel or hot pad. Never put your hands or face near the vent when releasing steam. Open the pressure cooker lid.
Mash the potatoes using a potato ricer or with a potato masher directly in the Instant Pot. Stir in the remaining 1 teaspoon kosher salt, butter, and cream. Taste, and adjust seasonings as desired. (You can add a little more salt, but if they’ll be served with butter or gravy it may not need it.) Garnish with chopped chives and fresh ground pepper.