My Go To crockpot recipe for potlucks is this: Take as many white mushrooms as will fit in a crock pot, add a stick or two of butter, an entire bottle of cooking sherry (which is just regular sherry with a bunch of salt in it, you could also buy cheap white wine and use that plus a bunch of salt), and whatever random Italian herbs I can lay my hands on (usually a ton of dried oregano, basil and rosemary, but I've even used one of those Italian dressing seasoning packets before). Basically it's done as soon as the mushrooms get soft, but the mushrooms will just keep getting better the longer it cooks -- and I never EVER take any leftovers home.
Another serving suggestion:
If you wanted to serve them with something, my old favourite restuarant had a mushroom sandwich that was a baguette toasted with garlic butter, herby buttery mushrooms, and then lots of goat cheese on top. It was so good. I immediately thought of it when I read Wendy's post.