1 pound dried black beans, (2 1/2 cups), 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, sliced
8 ounces tomatillos, (see Ingredient Note), husked, rinsed and coarsely chopped
1/4 cup water
5 1/2 cups mushroom broth, or vegetable broth
1 6-ounce can tomato paste
1-2 tablespoons minced canned chipotle peppers in adobo sauce, (see Ingredient Note)
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