I was certain I had posted the recipe for the stock before but I cannot find it. Both my wife and my roommate enjoy it greatly. My roommate says I have done the impossible: made a French onion soup gratinee where she doesn't miss the beef stock. Very few places around Boston can top it, and those places all use beef stock to the best of my knowledge.
Thus, what is likely a re-post: my recipe for vegetarian French onion soup gratinee. This is, I would say, about the equivalence in quality to non-vegetarian French onion soup that you will find in many fine restaurants.
( background and recipe below the cut. )