Divide the cauliflower into small florets. Cut the not so coarse stalk parts into leaves. Chop the greens coarsely.
Melt the butter in a saucepan.
Before it starts to brown, stir in the flour and toast well. Make sure it does not get dark. Pour in the vegetable soup.
While doing so, stir vigorously with a whisk. Bring to a boil briefly and then add the cauliflower florets and strunk slices to the soup.
Let the soup simmer gently for 10 to 15 minutes. Then stir in the cauliflower greens and season to taste with salt and pepper.