White bean chili with herbed yogurt cheese

3 cups dried navy or other white beans

2 small poblano chiles

1 tablespoon unsalted butter

4 cloves garlic, minced

1 onion, cut into 1/4-inch dice

1 large carrot, cut into 1/4-inch dice

2 stalks celery, cut into 1/4-inch dice

1 teaspoon ground cumin

1 teaspoon ground coriander

1/2 teaspoon paprika

1/4 teaspoon cayenne pepper (optional)

30 ounces homemade or low-sodium storebought chicken stock, skimmed of fat

8 cups water

1 1/2 teaspoons coarse salt

1/4 teaspoon freshly ground black pepper

4 radishes, grated

Cilantro sprigs, for garnish

Pick over the dried beans, discarding any stones or broken beans; rinse. Place in a large saucepan, cover with cold water by 2 inches, and bring to a strong boil over high heat. Cover, and remove from heat; let stand 1 hour. Drain the beans; set aside.
Meanwhile, place the peppers directly on a gas burner over high heat or on a grill. As they turn black, turn with tongs. (Alternatively, place the peppers on a baking pan; broil in the oven, turning as the peppers become charred.) Transfer the charred peppers to a medium bowl; cover with plastic wrap. Let the peppers rest 15 minutes. Transfer to a work surface (do not rinse). Peel off the blackened skin; discard. Halve the peppers; remove the seeds and ribs and discard. Cut the peppers into 1/4 -inch pieces; set aside.
Heat the butter in a large saucepan over medium heat. Add the garlic, onion, carrot, and celery. Cover; cook, stirring occasionally, until softened and slightly browned, about 15 minutes. Add the cumin, coriander, paprika, and cayenne, if using; stir to combine. Stir in the stock, water, beans, and half the roasted poblano chiles. Cover; cook until the beans are soft, about 11/2 hours. Uncover; simmer gently until the beans begin to fall apart, about 30 minutes more. Season with salt and pepper. Serve the chili garnished with the remaining poblano chiles, radish, cilantro, and yogurt cheese, if desired.

SERVES 6