Peel and dice the potatoes.
Add one cup of water to the Instant Pot.
Add in the potatoes, sprinkle in the garlic, salt, and pepper.
Place the lid on the Instant Pot, setting the valve to the sealed position.
Press the pressure cook/manual button, setting the timer to 5 minutes. *Note: It will take about 10 minutes to come to pressure, then cook another 5 minutes.
Once the Instant Pot releases all of the pressure, open the Instant Pot lid.
Fold in the Parmesan and butter.
Using a hand mixer, mix until it's the desired consistency.
Top with fresh diced parsley.
Plate, serve, and enjoy!