In a large dutch oven or pot, heat the oil over medium heat. Add in the onions and saute them until the onions are softened. Add the garlic into the pot and cook for an additional minute.
Stir in the beans, chicken stock, chicken, chillis, cumin, salt, and pepper. Turn the heat to high and allow the soup to come up to a boil. Once it comes to a boil, bring the heat down to low and cover. Allow it to simmer for 15 minutes.
Stir the Greek yogurt into the soup.
Serve with your favorite toppings like avocados, tortilla chips, sour cream, sliced jalapenos, cheese, lime wedges.