DELICIOUS!! I took the suggestion of Balsamic Vinegar & marinated the mushrooms in the Balsamic, a little Blood Orange Olive Oil & sprinkled with Vegetable Grilling Seasons. Did this on the Geo Foreman Grill & added some Vidalia Onion. Did everything else as recipe suggested. No bun or roll. Served it with a bowl of soup. A great vegetarian meal!!! Plan to do this recipe several times this summer on the outdoor grill. YUM!!