I know this is an old post, but thought I'd post this recipe for posterity so others coming along who see it will have a GOOD solution to this LC cook's dilemma. Of course, you can always just use cream, mushrooms and thicken it up heavily. But Jennifer Eloff at "Splendid Low Carbing with Jennifer" has a marvelous Condensed cream of Mushroom soup buried inside a recipe that is absolutely so close to Campbell's counterpart, it's the only recipe I use for this purpose now. Her recipe makes the equivalent to two cans of the soup. Best of all, there's no cooking!!! You whip this stuff up in a blender/processor in minutes! Here's a link to her chicken casserole she created the soup mix for, so just scroll down to see the soup recipe:
http://low-carb-news.blogspot.com/2...-casserole.html

You will NOT be sorry you tried this soup recipe!!!