To make a simple cauliflower soup, cook 1 head of cauliflower in 5 cups of chicken broth with thyme, and add 1 teaspoon of salt and 1/4 teaspoon of pepper. Transfer the soup to a blender to puree it before serving. Top the soup with toasted garlic slices, if desired.
To make an extra creamy cauliflower soup, combine 9 cups of cauliflower, 2 stalks of chopped celery, 1 chopped onion, 3 diced potatoes and 2 teaspoons of minced garlic in a large pot. Add 2 cups of chicken broth, 1 cup of water, and salt and pepper to the soup. Simmer the mixture until vegetables are tender. Mix 2 tablespoons of flour into 2 1/2 cups of milk, and add the mixture to the cauliflower. Stir the soup until it thickens slightly, and puree it before serving.
To make cold cauliflower soup, sauté 3/4 cup celery, 2 sliced shallots and 2 cloves of garlic in 3 tablespoons of butter, and add 1 head of cauliflower, 1 teaspoon of thyme and 4 cups of chicken broth to the soup. Add salt and pepper to taste. Cook the soup until the vegetables are tender, then puree the soup in a blender, and refrigerate it for 2 hours before serving. Top the soup with croutons or crispy bacon, as desired.