I knew someone out there would know how to make the sauce. And sorry Doreen. Guess I was a bit skimpy on the 'how to'. the portabella was about 4 inches across. My friend and I were sharing dishes so had half of the mush dish, but that was enough because it tasted so-o rich. What a delight it was. I had a small sake as well. I wonder what the carb count is on that?