Ingredients

BROTH

1. 2 quarts of water
2. 1/4 cup tomato paste
3. 3 large carrots, thickly sliced
4. 3 medium onions, coarsely chopped
5. Two 2-inch wedges of green cabbage (about 6 ounces)
6. 2 celery ribs, coarsely chopped
7. Trimmed stems from 1 fennel bulb
8. 6 thyme sprigs
9. 4 large garlic cloves, smashed
10. Salt

SOUP

1. 2 medium carrots, thinly sliced
2. 1 medium parsnip, cut into 1/4-inch dice
3. 1 large fennel bulb, stems trimmed, bulb halved, cored and thinly sliced lengthwise
4. 1 medium onion, minced
5. 1 small zucchini, cut into 1/4-inch dice
6. 4 plum tomatoes, cut into 1/2-inch dice
7. Salt and freshly ground pepper
8. Pistachio Pistou
9. Shavings from one 2-ounce piece of Parmesan cheese

Directions

1. MAKE THE BROTH: In a saucepan, whisk the water into the tomato paste. Add the carrots, onions, cabbage, celery, fennel stems, thyme and garlic. Season with salt and cook over low heat for 1 hour. Strain the broth into another large saucepan and discard the vegetables.
2. MAKE THE SOUP: Bring the broth to a boil. Add the carrots, parsnip, sliced fennel and onion. Reduce the heat to moderate, cover and simmer until the vegetables are tender, about 5 minutes. Add the zucchini and tomatoes, cover and simmer for 3 minutes longer. Season with salt and pepper.
3. Ladle the soup into shallow bowls and stir about 1/2 tablespoon of the Pistachio Pistou into each bowl. Top with the Parmesan shavings and serve.

Make Ahead

The soup can be refrigerated for up to 1 day.

Notes

To make the soup a little richer, add a Parmesan rind to the broth along with the vegetables and herbs and strain it out after everything simmers. If you would like to make the soup more substantial, add cooked rice or beans.