Cut the top off the bulb of garlic, about one-third of the way down, exposing the insides of most of the cloves. Place the bulb of garlic on a piece of aluminum foil, drizzle the olive oil over the top, and loosely wrap with the foil.
Roast for 40 minutes, until the cloves are golden brown and tender. When the garlic has been in the oven for 20 minutes, begin preparing the cauliflower mash.
Use a small spoon to gently scoop out the roasted garlic. Set aside 6 cloves for use in this recipe.
Make Cauliflower Mash
Core the cauliflower and chop the florets into small pieces.
Bring a large pot of salted water to a boil. Add the cauliflower and cook until tender, about 20 minutes. Drain, then set on a paper towel and pat dry.
Put the cooked florets along with the rest of the mash ingredients in a high-powered blender or food processor and blend just until smooth. Garnish with fresh parsley.
Instant Pot Method: Core the cauliflower and cut the florets into 3 to 4 large sections. Pour 1 cup of water into the Instant Pot and place the large cauliflower pieces inside. Lock the lid, then turn the steam knob to the " sealed" setting. Press the vegetable steam button. Once complete, transfer the steamed cauliflower to a colander to drain, then set on a paper towel and pat dry. Complete from Step 3 above to make the mash.