In a saucepan, heat the olive oil, add the sliced leeks, cook, stirring occasionally, about 5 minutes. Add the cauliflower florets and cook for about 5 minutes. Pour in the broth, cream, drop your bay leaf and coriander.
Bring to a boil over medium heat, stirring constantly. Cook until cabbage is very soft (about 45 minutes). Remove the bay leaf. Hand blender turn mass into a puree through a sieve and run soup. Season with salt and pepper.
Soup again put on the stove and keep on low heat to keep it warm.
Ladle the soup, put the sliced boiled egg, sprinkle seasoning to taste. Serve hot with croutons.