Portobello Steaks, The Happy Herbivore, p. 148
I liked this and I think the DH liked it. The Daughter would not touch it since "It's a mushroom, mom!"
I didn't add any salt at the end as suggested options, my broth was pretty salty as it was. (I used Mirin.) I think next time I would cut the mushrooms in strips so they would "fry" better in the pan. My thyme didn't pulverise well and it didn't have a good mouth-feel. I minced the onion, but I think nice big chunks would have been nice to eat, too.
Not really very filling all by itself, you really need a hearty side dish. The author suggests eating this with a baked potato or mashed potatoes and I think that's a good idea–eating it with something that one would normally have with a steak to "complete" the experience. It was a little lacking with just the carrots I made. I think you could double the amount of broth (if you make it from her recipe). My liquid evaporated pretty quickly and I was constantly pouring more in the pan.