PREPARATION
1. Heat the oil in a soup pot over medium-high heat. Add the lamb and cook, breaking up with a fork, until well browned, 5 minutes. Season with ½ teaspoon each of salt and pepper. Transfer meat to a paper towel-lined plate.
2. Add the onion and poblano peppers. Cook until the vegetables are softened, 5 to 7 minutes. Finely chop 2 tablespoons of the cilantro stems and add to the pot. Stir in the garlic and jalapeño and cook 2 minutes. Add the chile powder, coriander and cumin, and cook 1 minute. Stir in the tomato paste and cook until it begins to turn brown.
3. Return the lamb to the pot. Stir in 4 cups water, the beans and ¼ teaspoon salt. Simmer over medium-low heat for 45 minutes; add more water if the chili becomes too thick. Taste and adjust seasonings if necessary. Ladle into bowls, and top with a dollop of yogurt and a squeeze of lime. Garnish with chopped cilantro leaves.