Add cheese shortly before serving, stir until melted and incorporated.  I often add some cornmeal to thicken the soup a bit more, depending on my cooking mood.  There is a lot of rrom for flexibility with a soup like this.  Sometimes I use more meat, sometimes more beans, sometimes less broth, sometimes more cheese... I'll often play with spices and add oregano and cumin as well, it almost always turns out just a little bit different than it did the last time, but it always turns out good!
    Serve with some cornbread, plenty of corn tortilla chips (it's good with a handful crushed and mixed in), maybe some fresh chopped tomatoes and avacodos, whatever suits your fancy... oh, and for those with no 'white stuff' aversion- mix in some sour cream when serving.

    Now I need to jump up and stir, and get the corn bread in the oven.  Enjoy!
    ali