- 2 tablespoons olive oil
- 2 leeks (white and light green parts), sliced into half-moons
- 2 medium parsnips, peeled and cut into 1⁄4-inch pieces
- 1 large bulb fennel, cored and cut into 1⁄4-inch pieces
- kosher salt and black pepper
- 1/2 cup dry white wine
- 1 pound Yukon gold potatoes, peeled and cut into 1⁄2-inch pieces
- 5 cups low-sodium vegetable or chicken broth
- 1 small baguette, split horizontally
- 2 ounces grated Gruyère or Swiss cheese (1⁄2 cup)
- 1/4 cup chopped fresh dill
- Heat the oil in a large pot over medium heat. Add the leeks, parsnips, fennel, ¾ teaspoon salt, and ¼ teaspoon pepper.
- Cook, stirring occasionally, until the vegetables begin to soften, 6 to 8 minutes. Add the wine and simmer until evaporated, 1 to 2 minutes.
- Add the potatoes and broth and bring to a boil. Reduce heat and simmer until the potatoes are tender, 12 to 15 minutes.
- Transfer half the mixture to a blender and puree until smooth. Return it to the pot.
- Meanwhile, heat broiler. Place the bread, cut-side up, on a baking sheet and sprinkle with the cheese. Broil until the cheese melts. Cut into pieces.
- Sprinkle the soup with the dill and serve with the cheese toast.