Carefully prep cauliflower as directed above, trying to keep the florets intact; try pulling them apart by hand or cutting by using the knife from the bottom of the floret to the top so it separates cleanly.
Add one cup water to the bottom of the Instant Pot, add the rack and evenly arrange florets across the top. Add the lid, seal and set to low pressure for two minutes…BUT…the cauliflower needs to cook for 1 1/2 minutes.
Watch the instant pot carefully after it comes up to pressure (this will take about five minutes) and after the first minute of cooking, count (or use a timer) cook for 30 more seconds. Immediately manually release the pressure.
Remove the rack & the cauliflower as soon as the pot is able to be opened, then remove the liner and any stray florets that have fallen through the rack into the liner. Discard water and put liner back in the instant pot without the rack. Set to saute. Add oil or butter if using. Add the florets back to the pot and using a potato masher, break the cauliflower down to small pieces.
Cook to desired doneness, a minute or two to dry the rice, a little longer if you’d like a bit of color. Add salt to taste.