Place the cauliflower florets in a saucepan and add enough water to cover them.
Add the stock cube and bay leaf, bring to the boil, then reduce the heat and simmer for 5 minutes.
Add the cannellini beans and continue cooking for another 5 minutes, or until the cauliflower is completely tender.
Remove the bay leaf and drain, reserving a little of the cooking liquid.
Using a stick blender or potato masher, blend the cauliflower and beans until smooth, adding a little of the reserved cooking liquid to reach your preferred consistency.
Stir in the minced garlic, butter and the chopped herbs.
If using, mix in the Parmesan, feta, Greek yoghurt or another cheese until melted or well combined.
Season with salt and freshly ground black pepper to taste and serve warm.