Black Bean Chilaquiles

1 1/4 cups dried black beans, soaked overnight
6 cups chicken broth
1/2 white onion, chopped
3 garlic cloves, chopped
2 canned chipotle chiles, seeds removed
1 teaspoon salt
8 ounces tortilla chips
Sour cream for garnish
Diced avocado for garnish
Cilantro for garnish
Cotija cheese for garnish

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, pur