Italian White-Bean-and-Mustard-Greens Soup
Mustard greens have a sharp, radishy bite that's delicious in a bean soup, but, if you like, you can substitute kale or collards. Smaller white beans such as cannellini can be used in place of giant white beans.
- 1 pound dried giant white beans, such as gigante, Corona, or lima
- 3 tablespoons extra-virgin olive oil, plus more for drizzling
- 1 onion, finely chopped (1 1/4 cups)
- 2 medium carrots, cut into 1/4-inch dice (1 cup)
- 4 cloves garlic, minced
- 1 1/2 pounds mustard greens, washed well and stems removed, cut crosswise into 1/2-inch-thick strips
- 5 thyme sprigs
- 5 flat-leaf parsley sprigs
- 2 bay leaves
- 1 Parmesan cheese rind (about 1 by 4 inches; optional), plus freshly grated Parmesan cheese, for sprinkling
- 2 quarts water
- Coarse salt and freshly ground pepper
- 1 cup farro
Place beans in a large bowl, cover with 2 inches cold water; let soak overnight at room temperature. Drain and rinse beans. (Or quick-soak them: Boil beans 1 minute, then let them sit off heat, covered, 1 hour.)
Preheat oven to 300 degrees. Heat oil in a large, heavy-bottomed ovenproof pot over medium-high heat. Add onion and carrots, and cook, stirring occasionally, until vegetables are golden brown in places, 8 to 10 minutes. Add garlic and greens to pot, and cook, stirring frequently, until greens wilt, about 2 minutes.
Tie together thyme, parsley, and bay leaves with kitchen twine, and add to pot along with beans, Parmesan rind, and water. Bring to a boil over high heat. Cover, transfer to oven, and braise 1 hour.
Remove from oven, and stir in 1 tablespoon salt and 1/2 teaspoon pepper. Cover, return to oven, and braise until beans are tender, about 30 minutes. Season with salt and pepper.
Meanwhile, bring a large pot of salted water to boil. Add farro, and cook until grains are tender and begin to split, about 25 minutes. Drain.
Divide farro among 6 bowls, and ladle soup over farro. Sprinkle with Parmesan, and drizzle with oil. Soup and farro can be refrigerated in separate containers 2 days; let cool completely before refrigerating. Gently reheat together in a covered pot over medium heat, stirring occasionally.