Asian Vegetarian mushrooms - serve 'em up with pasta or brown rice:
in a high-sided sauce pan, saute a handful or two of chopped shallots (onion will do in pinch, but not as good)
throw in a box or two of white button mushrooms - you don't need to chop 'em, just clean 'em and trim stems (Any kind of mushrooms will do...)
brown for a few minutes, then add 1/4 cup soy sauce, 1/4 cup seasoned rice wine vinegar and a few turns of crushed black pepper.
Cover sauce-pan and simmer for five or ten minutes. The longer it sits, the better it is.
Add a pat or two of butter at the last minute if you're not concerned about fat/dairy.
Great over meat, rice, pasta - or on its own as a "soup".