Gather your three ingredients: a head of romanesco broccoli, a potato and a leek. Chop the potato into small cubes, break the broccoli into florets, and thinly slice the leak.
You will also need olive oil, sea salt and pepper.
And a large soup pot.
Add some olive to a large, heavy pot and warm.
Add leaks and sauté at low medium heat until soft. This should take 5 to 8 minutes.
Add the broccoli florets and the potato and sauté for about 5 minutes.
Add enough vegetable stock to cover, about 4 cups.
Cook until the broccoli is tender, about 20 minutes.
Let cool for a couple of minutes. Add salt and pepper to taste, then use an immersion blender to purée.
Pour into soup bowls, and swirl a little olive oil on top.