Peel potatoes. Add 1 cup water to the bottom of an instant pot. Add trivet. Place peeled potatoes on top of trivet. Lock lid; set valve to sealing. Program for manual-high and 20 minutes. Allow for natural pressure release.
Remove potatoes and mash. I use an immersion blender, but a potato masher or even a fork will work also.
To Freeze
Add mashed potatoes to a freezer-safe container, in any quantity you desire. (I freeze them in 4 serving quantities in quart freezer bags.) Freeze.
To Heat After Freezing
remove from bag and place frozen potatoes in a microwave-safe dish. Cover and vent. Microwave on high 2 minutes. Stir. Microwave 2 minutes longer. Check. If they’re not hot enough, microwave on high in 30 sec increments, stirring after each increment, until they’ve reached desired temperature.
Notes
Variations:Add 1 tablespoon unsalted butter per 4 potatoes before pureeing.Add 1 tsp cinnamon and 1 Tablespoon pure maple syrup per 4 potatoes before pureeing.