This recipe is from Deborah Madison's Vegetarian Cooking for Everyone, a book I've owned for years and years. It's the cookbook I always recommend to people asking for a good vegetarian cookbook, but looking through it with my new vegan eyes, I had a hard time finding recipes without dairy or eggs.
Anyway, I picked her portobello stew for this week and, once again, decreased the oil by about a third. She called for the soup to be primarily seasoned with rosemary, which Ben thinks is the devil, so I used thyme instead. In this recipe, onion and garlic are sauteed with a bunch of mushrooms, and then you stir in a little tomato paste, vinegar, and the herbs. And that's pretty much it. I served it over mashed potatoes.
It's not very pretty! But it was tasty. However, it wasn't very hearty - if I make this again, I will include some seitan to fill it out.