I tried this the other day and didn't have high expectations, but it was actually quite yummy.

Cream of Cauliflower Soup

1 (1-pound) head cauliflower, cut into small florets, divided use
1/4 cup butter or margarine
1 medium onion, chopped
1 leek (white and pale green parts only), chopped
3/4 cup chopped celery
1/4 cup all purpose flour
3 cups vegetable or chicken broth
1 cup (or more) milk
Salt and white pepper to taste

Blanch 1 cup cauliflower florets in medium pot of boiling salted water until just crisp-tender, about 2 minutes. Drain. Rinse under cold water; drain well. Set aside.

Melt butter in heavy large saucepan over medium heat. Add onion, leek, celery, and remaining cauliflower. Cover and cook until onion is tender but not brown, stirring frequently, about 8 minutes.
Add flour and stir 2 minutes. Gradually stir in vegetable broth. Add 1 cup milk. Bring mixture to a boil. Reduce heat. Cover partially and simmer until vegetables are very tender and soup thickens, stirring occasionally, about 20 minutes.

Puree soup in blender in batches until smooth. (Caution! Hot liquids create steam which will blow the top off the blender! Be sure to securely hold blender lid down!) Return to same saucepan and heat thoroughly. Season to taste with salt and white pepper.
Ladle soup into bowls. Garnish with reserved cauliflower and serve.

Makes 4 servings.