Steam your cauliflower and 1 clove of garlic in the vegetable stock until it's tender, about 15 minutes.
While the cauliflower is steaming, melt the butter in a small sauce pan with the herbs (medium-low heat.)
Strain the excess liquid from the cauliflower and transfer it to a large bowl. Discard the garlic clove.
Pour the melted butter over the cauliflower and smash with a masher or mixer. Season with salt and pepper to suit your taste.