- 1 medium leek (white and pale green parts only), halved lengthwise, then cut crosswise into 1/2-inch-thick slices (3/4 cup)
- 1 teaspoon unsalted butter
- 1 tablespoon water
- 1 (2-lb) head cauliflower, cored and cut into 1-inch pieces (6 cups)
- 3/4 teaspoon ground coriander
- 1 3/4 cups fat-free reduced-sodium chicken broth (14 fl oz)
- 1 1/4 cups 1% milk
- 1 1/4 teaspoons salt
- 1/4 teaspoon black pepper
- 1 tablespoon sliced almonds
- Wash leek slices in a bowl of cold water, agitating, then lift out and pat dry.
- Melt butter with water in a 4- to 5-quart heavy saucepan over moderate heat. Add cauliflower and leek and cook, uncovered, stirring occasionally, until cauliflower begins to soften (do not let brown), about 5 minutes. Add coriander and cook, stirring, 1 minute, then add broth, milk, salt, and pepper and bring to a simmer, stirring occasionally. Reduce heat and gently simmer, covered, stirring occasionally, until cauliflower is very tender, 15 to 20 minutes.
- While soup is cooking, toast almonds in a dry skillet over moderately low heat, stirring frequently, until fragrant and a shade darker, about 3 minutes.
- Purée soup in 2 batches in a blender (use caution when blending hot liquids) until very smooth. Serve soup topped with almonds.