Roasted Cauliflower Soup with Brown Butter or Harissa

Roasting the cauliflower gives profound flavor to this velvety – and super easy to make – puréed soup. Swirl in a little brown butter before serving to spin it French, or garnish it with harissa sauce for a delicious North African flavor. It's hard to imagine something dairy-free could be so rich-tasting, elegant and low-calorie (there are only about 100 calories per serving; add about 35 if you're garnishing with brown butter). Harissa is available in tubes or jars in supermarkets with well-stocked international sections.

For a vegan version, use vegetable broth rather than chicken broth, and choose harissa or another vegan garnish.

Makes 6 servings.

Ingredients

For the soup:

1 1/2 cauliflowers (about 1 3/4 pounds)

1 tablespoon olive oil

6 cups chicken broth (or vegetable broth)

1/2 teaspoon freshly ground white pepper, or to taste

Salt, if necessary

Brown butter garnish:

2 tablespoons butter

Harissa garnish:

2 teaspoons harissa

2 tablespoons chicken broth

Instructions

1. Heat the oven to 425 degrees. Remove the stems from the cauliflowers, break them into large chunks and lay them on a baking sheet (lined with a Silpat if you like, but it's not necessary). Brush the chunks with the olive oil and roast till the cauliflower is starting to be tender and a bit charred on the edges, about 40 minutes.

2. Place the cauliflower in a soup pot with the chicken broth (or vegetable broth) and bring to a boil over high heat. Reduce heat to medium and simmer, uncovered, until the cauliflower is very soft, about 12 to 15 minutes. Use an immersion blender, food processor or blender to purée the soup until very smooth, and then purée it a little more. Add the white pepper and taste for salt, adding more if necessary (depending on how salty your chicken broth was, you may not need any).  The soup may be garnished and served immediately, or keep it covered in the refrigerator up to one day until ready to reheat on the stove, garnish (or not) and serve.

3. For the brown butter garnish, melt the butter in a small sauce pan and cook it over medium-low heat, swirling it in the pan every couple of minutes, until it is nut brown. For the harissa garnish, combine the harissa and chicken broth in a small bowl. For either garnish, divide the soup into bowls, and use a small spoon to swirl the brown butter or harissa sauce in each.