We like The Mushroom Thing a lot. I think I make it at least once a month. I guess an open-faced mushroom sandwich would be a more accurate name. But since it has sauteed spinach on it and we eat it with a knife and fork, I don't really think of it as a sandwich. So, when Steve asks "What's for dinner?," I just say "the mushroom thing."
A Deborah Madison recipe is the original source of the recipe, but with the addition of the slow roasted tomatoes and a drizzle of sun-dried tomato vinaigrette, I think I've made it my own. A marinated and grilled portobella 'shroom is filled with garlic-sauteed spinach and a few oven-dried tomatoes and topped off with fresh mozzarella. It goes in the oven to warm and melt the cheese. The mushroom thing is served on top of toasted french bread. More tomatoes are added to the plate and vinaigrette is drizzled around. Voila!