Salt turns out to be the key for ultratender white bean soup

The people of Tuscany are known as mangiafagioli, or “bean eaters,” a nod to the prominent role beans play in their cuisine. Cannellini (white kidney) beans are the region’s most famous legume, and Tuscan cooks go to extremes to ensure these beans are cooked perfectly, from simmering them in rainwater to slow-cooking them overnight in a wine bottle in a fire’s dying embers.

Zuppa di fagioli alla toscana is a quintessential bean dish featuring an aromatic base, hearty greens, tomatoes, pancetta and, of course, creamy, buttery beans. Soaking the beans overnight was essential to soften them so their interiors cooked up creamy. And salting the soaking wateressentially briningsoftened the skins until they were barely perceptible for ultratender beans.

After experimenting with cooking times and temperatures, we found that a vigorous stovetop simmer caused some beans to explode, so we gently cooked them in a 250 F oven for even results. Adding the tomatoes toward the end of cooking ensured their acidity wouldn’t toughen the beans.

Tuscan White Bean Soup

Servings: 8. Start to finish: 2 hours (not counting at least 8 hours soaking time)

Salt and pepper

1 pound (2 1/2 cups) dried cannellini beans, picked over and rinsed

6 ounces pancetta, cut into 1/4-inch pieces

1 tablespoon extra-virgin olive oil, plus extra for serving

1 onion, chopped

2 carrots, peeled and cut into

1/2-inch pieces

2 celery ribs, cut into 1/2-inch pieces

8 garlic cloves, peeled and smashed

4 cups chicken broth

Water

2 bay leaves

1 pound kale or collard greens, stemmed and chopped

1 (14.5-ounce) can diced tomatoes, drained

1 sprig fresh rosemary

Dissolve 3 tablespoons salt in 4 quarts cold water in large container. Add beans and soak at room temperature for at least 8 hours or up to 24 hours. Drain and rinse well.

Adjust oven rack to lower-middle position and heat oven to 250 F. Cook pancetta and oil in Dutch oven over medium heat, stirring occasionally, until pancetta is lightly browned and fat is rendered, 6 to 10 minutes. Stir in onion, carrots, and celery and cook until softened and lightly browned, 10 to 16 minutes. Stir in garlic and cook until fragrant, about 1 minute. Stir in broth, 3 cups water, bay leaves, and beans and bring to boil. Cover, transfer pot to oven, and cook until beans are almost tender (very center of beans will still be firm), 45 minutes to 1 hour.

Stir in kale and tomatoes, cover, and cook until beans and greens are fully tender, 30 to 40 minutes.

Remove pot from oven and submerge rosemary sprig in stew. Cover and let sit for 15 minutes. Discard bay leaves and rosemary sprig and season stew with salt and pepper to taste. If desired, use back of spoon to press some beans against side of pot to thicken stew. Drizzle individual portions with extra oil before serving.

Nutrition information per serving: 367 calories; 96 calories from fat; 11 g fat (3 g saturated; 0 g trans fats); 14 mg cholesterol; 483 mg sodium; 48 g carbohydrate; 17 g fiber; g sugar; 19 g protein.