- In a saucepan, soften the leek in the butter. Add the potatoes, zucchini, and water. Season with salt and pepper.
- Bring to a boil. Cover and simmer over medium heat for 15 minutes or until the potatoes are very tender.
- In a blender, purée the soup until smooth. Add the cream and adjust the seasoning.
- Let cool and refrigerate until completely chilled, about 4 hours.
- Just before serving, garnish each bowl with a zucchini flower. Serve with toasted bread drizzled with olive oil and sprinkled with sea salt.