Adjust oven rack to middle position and heat oven to 400 degrees. If using a Pot of Beans, soak, cook, and drain them.
Heat oil in a large pot; add onions and sauté until nearly tender, about 4 minutes. Add garlic, cumin, smoked paprika, and oregano; continue to cook another minute or so. Add broth, beans, tomatoes, and rice; bring to a simmer. (*If using chiles in adobo, add it now.)
While mixture heats, crumble tortilla chips.
When mixture starts to simmer, stir in cilantro. Taste and adjust seasonings, including salt and pepper to taste. Turn mixture into a 13- by 19-inch pan; sprinkle with tortilla chips and bake until bubbly and golden brown, about 30 minutes. Remove from oven, (*If using scallions, sprinkle them now.). Let rest a few minutes, and then serve.