Peel the potatoes and cut them into 1-inch pieces.
Put potatoes and water in the Instant Pot, close the lid and turn the valve to Sealing position. Press the "Pressure Cook" or "Manual" button and set the time to 3 minutes on High pressure.
When the Instant Pot is done cooking, quick release (QR) the steam and drain the potatoes.
Dry the empty pot and put it back into the Instant Pot. Pour oil in the Instant Pot, leave the pot open, press the "Saute" button and select 15 minutes for the time. Let the oil heat for 2 minutes, then add the potatoes in a single layer.
Let the potatoes cook undisturbed for 3 minutes, then flip them over and cook on another side for 2 minutes. Stir the potatoes again and saute for another 2 minutes or until golden brown all over.
Sprinkle the roasted potatoes with salt and pepper to taste and serve.