Preheat oven to 400°F. Slice the top off the head of garlic, place on a square of foil, drizzle with a little of the oil, and close up the foil packet. Toss the cauliflower and onion pieces with remaining oil, spread out on a baking dish, season with salt and pepper, and bake all for 30-40 minutes until tender and lightly browned.

While cauliflower, onion, and garlic are baking, add a little oil to your soup pot and cook the carrots, stirring occasionally, until softened. Squeeze the baked garlic cloves out of their papery skins (or scoop out with butter knife) and add to soup pot along with the cauliflower and onion.

Blend to your desired consistency, chunky or smooth, with a regular or immersion/stick blender. Stir in cheese until melted. If too thick, or if desired, you can also stir in some butter and/or cream (or milk). Taste for seasoning and adjust as needed.

Serve hot, topped as desired.