To steam the cauliflower in the Instant Pot, place the steam basket inside the Instant Pot. If you don't have the steam basket, you can use the wire rack that the Instant Pot comes with. Pour 1 cup water in the Instant Pot. Place cauliflower in the basket or on top of wire rack.
Put the Instant Pot lid on and turn until locked. Cook on high pressure for 4 minutes and then do a quick release. Carefully unlock the lid and place the cauliflower in a large bowl.
Heat the olive oil in a small skillet over medium heat and add the minced garlic. Cook for 2 minutes. Pour the cooked garlic into the bowl with the steamed cauliflower. Add the butter and herbs.
Use a hand held immersion blender to mash the cauliflower to desired consistency. Don't over mix or you will end up with a cauliflower puree. You can also use a potato masher. Season the mashed cauliflower with salt and pepper, to taste. Serve warm.
If you don't have an Instant Pot, you can steam the cauliflower on the stove top using a steam basket. Steam for 6 to 8 minutes.