French Winter Vegetable Soup

French Winter Vegetable Soup
serves 6

This recipe is a model for a classic winter vegetable soup. It has a purity of flavor that can be achieved only by using water as the cooking medium, rather than broth. After half an hour or so of cooking together, the flavors of the vegetables coalesce into a thick savory soup that is both nourishing and comforting. A little olive oil is incorporated to add body and harmonize flavors.

This recipe has infinite permutations: You can include or substitute other vegetables or add a chunk of smoky ham or herbs. I often add shredded cooked chicken or lamb, thin slices of smoked duck, or cooked dried beans to make it more substantial. You can also pass grated sheep’s milk cheese or Parmigiano–Reggiano on the side. Sometimes I pound fresh herbs, such as basil, chervil, and flat–leaf parsley, with small amounts of stronger herbs, such as thyme and rosemary, in a mortar with a little olive oil to spoon into the soup rather than the plain olive oil (see Guide, page 589).

Serve the soup with pan–grilled Rustic Garlic Toasts (page 368) and mesclun salad.

6 cups water
3 tablespoons extra-virgin olive oil
2 teaspoons kosher salt
1 medium onion, cut into 1/4-inch dice
2 medium Yellow Finn or Yukon Gold potatoes (about 3/4 pound),
peeled and cut into 1/4–inch dice
3 medium leeks, white and pale green parts only, thinly sliced
and rinsed to remove grit
3 to 4 medium carrots (8 ounces), peeled and cut into 1/4–inch dice
3 medium parsnips (6 ounces), peeled and cut into 1/4–inch dice
2 medium turnips or 1/2 rutabaga (8 ounces), peeled and cut into 1/4–-inch dice
1 small celery root (8 ounces), peeled and cut into 1/4–inch dice
1 small fennel bulb, trimmed, cored, and cut into 1/4–inch dice
2 garlic cloves, smashed
Freshly ground black pepper

In a large heavy saucepan, bring the water, 2 tablespoons of the olive oil, and salt to a boil. Add the vegetables and garlic and simmer, half covered, until the vegetables are very tender, about 30 to 35 minutes. Pepper liberally.

Ladle into bowls and drizzle about 1/2 teaspoon of the remaining olive oil over each serving.

in advance: The soup will keep for up to 4 days, covered, in the refrigerator.