Sautee onions in olive oil over medium heat until softened. Add peppers and chiles and sautee for another 5 minutes. Add garlic and sautee until fragrant, about 1 minute. Add chicken broth, beans, cumin and toamatillos. Stir in shredded chicken. Simmer gently stirring occasionally for 45 minutes to an hour. Stir in cilantro 5-10 minutes prior to serving. Granish with sour cream, cheese and additional cilantro.