- Preheat the oven 180°C/gas mark 4 and lightly oil a baking sheet.
- Break ¼ of the cauliflower into very small florets, rinse in cold water, shake off any excess and add to a bowl. Sprinkle with the turmeric and mix well. Place on the baking sheet and roast for 10-15 minutes until the edges are starting to char, then set aside.
- Meanwhile, add 2 tsp oil to a pan and add the onion. Cook for 3-4 minutes until softened, but not browned. Add the leeks and the rest of the cauliflower and cook a further 3-4 minutes, stirring regularly.
- Add the cumin, garlic, pepper and stock and bring to the boil. Turn down the heat, cover, and simmer gently for 8-10 minutes until the cauliflower is cooked.
- Add the butter beans and blend gradually, adding the milk until smooth. Bring up to heat then divide between 6 bowls and top with the roast cauliflower and a good grind of black pepper.
- You could try other beans, such as flageolet for this soup.
- Try adding 1-2 tsp curry paste or powder to the soup along with the garlic and cumin.
- You can make the soup in advance and reheat - don’t top the dish with the cauliflower croutons until just before serving.;
- Freezing instructions: Suitable for freezing once cooked. Freeze cauliflower croutons separately. Defrost in a microwave or over a very low heat until piping hot.