Separate cauliflower into florets and cut in smaller chunks.
In a medium pot, combine cauliflower, garlic and enough cold water to cover the vegetables. Place a lid on top and bring to a boil. Reduce heat to low and cook for about 10 minutes or until cauliflower is fork tender. Drain.
Add butter or olive oil, salt and ground black pepper to taste. Using an immersion blender (a food processor), process until very smooth or desired consistency. Adjust salt and pepper to taste, if necessary.
Serve hot just like you would serve mashed potatoes.