Place a steamer rack or trivet with handles in the bowl of the Instant Pot, and add the water.
Remove the core and cut the cauliflower into large pieces.
Place the cauliflower on the trivet and secure the lid on the Instant Pot. Move the vent knob to the sealed position.
Select “Manual” and cook for 4 minutes on high pressure.
Carefully open the vent to quickly release the pressure.
Open the lid and remove the trivet and cauliflower. Drain the water and place the cauliflower back into the inner bowl.
Add the ghee, salt, pepper, and garlic powder, and puree using an immersion blender.
Garnish with chives if desired.