Preparation time: 6 1/4 to 9 1/4 hours
1 pound dried black beans (2-1/2 cups), picked over and rinsed
1 tablespoon extra-virgin olive oil
1/4 cup mustard seeds
2 tablespoons chili powder
1 1/2 teaspoons cumin seeds or ground cumin
1/2 teaspoon cardamom seeds or ground cardamom
2 medium onions, coarsely chopped
1 pound mushrooms, wiped clean, trimmed and sliced (4-1/2 cups)
8 ounces tomatillos, husked, rinsed and coarsely chopped
1/4 cup water
5 1/2 cups mushroom broth or vegetable broth, homemade or canned
1 6-ounce can tomato paste
1 to 2 tablespoons minced canned chipotle peppers in adobo sauce
1 1/4 cups grated Monterey Jack or pepper Jack cheese
1/2 cup reduced-fat sour cream
1/2 cup chopped fresh cilantro
2 limes, cut into wedges
1. Soak beans overnight in 2 quarts water. (Alternatively, place beans and 2 quarts water in a large pot. Bring to a boil. Boil for 2 minutes. Remove from heat and let stand for 1 hour.) Drain beans, discarding soaking liquid.
2. Meanwhile, combine oil, mustard seeds, chili powder, cumin and cardamom in a 5- to 6-quart Dutch oven. Place over high heat and stir until the spices sizzle, about 30 seconds. Add onions, mushrooms, tomatillos and 1/4 cup water. Cover and cook, stirring occasionally, until vegetables are juicy, 5 to 7 minutes. Uncover and stir often until the juices evaporate and the vegetables are lightly browned, 10 to 15 minutes. Add broth, tomato paste and chipotles (with sauce); mix well.
3. Place the beans in a 5- to 6-quart slow cooker. Pour the hot mixture over the beans. Turn heat to high. Put the lid on and cook until the beans are creamy to bite, 5 to 8 hours.
4. To serve, ladle the chili into bowls. Garnish each serving with cheese, a dollop of sour cream and a sprinkling of cilantro. Pass lime wedges at the table.
Stovetop method: Total: 4 1/2 hours In Step 2, increase broth to 8 1/2 cups. Omit Step 3. Add the beans to the Dutch oven; cover and simmer the chili gently over low heat, stirring occasionally, until beans are creamy to bite, about 3 hours.