Place the cauliflower florets and garlic cloves in a large pot and cover with water. Bring to a boil over high heat, then reduce to a simmer and cook until the cauliflower is very tender, about 10-12 minutes.

Drain the cauliflower and garlic, then return them to the pot or transfer to a large bowl. Add the low-fat milk, butter, and a pinch of salt and pepper.

Using an immersion blender or a regular blender, purée the mixture until smooth and creamy. Adjust the seasoning with additional salt and pepper if needed.

Serve the mashed cauliflower hot, with an extra pat of butter on top if desired.