To a slow cooker chicken, I added an old family noodle recipe. If you want it to be more like a soup, add another quart of broth. This was a fixture at family reunions when I was a child, and the slow cooker makes it even easier.
A simple, weeknight carrot soup recipe finished with a thread of toasted sesame oil. You can leave it slightly chunky, or puree it until smooth - whatever your preference.