Drain the beans and combine in a large pot with the chicken broth,
onion, garlic, chiles and salt. Simmer partially covered until the
beans are very tender, about 2 hours. Add water if necessary to
keep the beans completely submerged.
Let the beans cool.
In batches, puree the beans in a blender, adding more water as needed
to create a thin soup like consistency. Taste and season the puree
with salt. You may complete this step several days in advance and
store in the refrigerator. Bring the black bean puree to a boil
in a large pot. Add the tortilla chips and stir frequently until
the chips have softened, but are still a little chewy.
Spoon into a serving dish, garnish and serve immediately.