Remove leaves and core, then cut into evenly sized florets. Smaller pieces cook faster and blend smoother.
Add 1–2 inches of water to a pot, insert a steamer basket, and bring to a simmer. Add cauliflower, cover, and steam until very tender, 10–12 minutes. It should be easily pierced with a fork.
Transfer the florets to a dry pot or pan and cook on low heat for 1–2 minutes, stirring. This evaporates excess moisture—key for ultra-creamy mash.
In a small skillet, gently cook the smashed garlic in butter over low heat until fragrant, about 1–2 minutes. Don't brown it. Remove the garlic if you prefer a subtler flavor.
Add cauliflower, melted garlic-butter, cream (start with 3 tablespoons), cream cheese (if using), salt, and pepper to a food processor or high-speed blender. Blend until smooth and glossy, scraping the sides as needed.
Add the remaining cream a little at a time until the mash is silky. For a thicker, more rustic feel, switch to a potato masher and skip extra liquid.
Stir in Parmesan if using. Taste and add more salt, pepper, or a splash of olive oil for richness. A squeeze of lemon can brighten things up.
Spoon into a warm bowl, garnish with chives or parsley, and finish with a pat of butter or olive oil drizzle. Try not to eat it all before dinner.