Trim the cauliflower and discard the leaves. Separate the florets and discard the tough stem. Put the cauliflower in a saucepan and cover with water; add the minced garlic, if using, and about 1/2 teaspoon of salt.

Place the pan over high heat and bring the cauliflower to a boil. Cover the pan and reduce heat to medium-low. Continue boiling for about 15 minutes, or until the cauliflower is very tender. Drain well.

Mash the cauliflower lightly with a potato masher and transfer it to a fine mesh strainer set over a bowl. Press the cauliflower with a large spoon or the bottom of a cup to press out as much moisture as possible.

Put the cauliflower in a food processor with the cream and the butter. Process until smooth. Alternatively, use a potato masher for a coarser texture.

Season with salt and freshly ground black pepper.