01 - Preheat oven to 400°F. Slice the top off the garlic bulb to expose the cloves. Drizzle with olive oil, wrap in aluminum foil, and roast for 30 to 35 minutes until soft and golden brown.
02 - Meanwhile, bring a large pot of salted water to a boil. Add cauliflower florets and cook for 10 to 12 minutes until very tender. Drain well and allow excess moisture to evaporate.
03 - Squeeze roasted garlic cloves from their skins and add to a food processor with the drained cauliflower, butter, cream cheese, milk, salt, and pepper. Blend until smooth and creamy, scraping down sides as needed.
04 - Adjust seasoning to taste. Transfer to a serving bowl, garnish with chives if desired, and serve warm.