Preheat the oven to 450 degrees. Slice the top off of the garlic head. Drizzle with olive oil, sprinkle with salt and wrap in foil. Roast until soft and caramelized, about 30 minutes.
Cook the cauliflower florets according to the package instructions, either by microwave or stove top method.
Drain the cauliflower and add to a food processor (or large bowl to mash with a potato masher or fork) and add the roasted garlic, butter, yogurt, Parmesan cheese, salt and pepper to the cauliflower. Pulse or mash until well-combined and process to desired consistency.
If short for time you can use jarred minced garlic instead of roasting the fresh garlic.