- 1 large onion, finely chopped
- 2 medium carrots, thinly sliced crosswise
- 1 celery rib (from inner part of bunch), thinly sliced
- 3 garlic cloves, finely chopped
- 1 Turkish or 1/2 California bay leaf
- 1 teaspoon salt
- 3 tablespoons olive oil
- 1 tablespoon tomato paste
- 2 cups reduced-sodium chicken broth (16 fluid ounces)
- 2 cups water
- 1 (19-ounce) can chickpeas (2 cups), rinsed and drained
- 1/2 teaspoon black pepper
- 5 ounces baby arugula (8 cups loosely packed)
- Accompaniments: coarsely ground black pepper; finely grated Parmigiano-Reggiano
- Cook onion, carrots, celery, garlic, and bay leaf with 1/2 teaspoon salt in oil in a wide 5- to 6-quart heavy pot over moderately high heat, stirring occasionally, until vegetables are softened, about 5 minutes. Stir in tomato paste and cook, stirring, 1 minute. Add broth, water, chickpeas, 1/4 teaspoon pepper, and remaining 1/2 teaspoon salt and simmer briskly, covered, until vegetables are tender, about 15 minutes.
- Discard bay leaf. Transfer 1 cup soup to a blender and purée, then stir back into soup. Stir in arugula and remaining 1/4 teaspoon pepper and cook just until arugula is wilted, about 1 minute.