I was looking for something that was only a 'little risky' for a potluck, so mushroom and mint sounded just about right. I wasn't sure about the combination either, but it was a hit.
Having said that, adjustments needed to be made. An entire quart of cream is way too much -- half that is about right.
Four onions is pushing it as well. I had only small onions, and slicing three seemed to be more than enough.
Make such adjustments and you're good to go.