One of my aunt's friends actually taught me this recipe. I think the first time I ate this I was about 12. Loved it and have made it since, well since I have been cooking. Ideally it is made on the BBQ but my hubby wasn't home and I have a fear of the BBQ... I promise I'll get over it some day soon, but for now, the oven is what I used. You can also cook your mushrooms in the toaster oven if you are making this for 2.
Mushrooms remain very active after harvest compared to most produce, and may even continue to grow. During four days storage at room temperature, they lose about half of their energy reserves to the formation of cell-wall chitin. The wait actually adds to their flavour! (On Food and Cooking by Harold McGee)