Melt the butter in a large pot over medium heat. Add chopped bell pepper, onion, carrot, jalapeño, and a pinch of salt. Stir the vegetables to coat in the butter, and let cook for 8-9 minutes until very soft and slightly browned.
Stir in minced garlic, ancho chili powder, cumin, Mexican oregano, and black pepper. Cook one minute.
Stir in black beans, fire-roasted tomatoes, chicken broth, shredded chicken, and salsa verde. Stir to combine, and simmer over medium for 15-20 minutes. Taste as it cooks, and season with more salt, pepper, or other seasonings if you like!
Squeeze in the fresh lime juice, and stir to combine. Spoon the soup into bowls, and garnish with crushed tortilla chips and your other favorite toppings, such as sour cream, avocado, shredded cheese, pico de gallo, or cilantro!