WHAT YOU DO
Step 1. Wash the cauliflower, remove the stalk and chop into florets. Peel the potato and dice. Finely slice the onion.
Step 2. Heat the butter and oil in a large saucepan and add the veg. Allow to sweat over a low heat for at least ten minutes. Do not allow to colour.
Step 3. Pour in the stock and bring to the boil. Return to a simmer, add the milk, season and simmer uncovered for about 20 minutes until all the vegetables are soft.
Step 4. Purée until very smooth. Add the cream, stir and serve with crispy croutons.
TIP: More interesting garnishes include crispy bacon, truffle oil, sautéed mushrooms or some crumbled blue cheese.