Recently I have been making Crimini mushrooms like this:
It tastes really good. I like how the mushrooms are very soft and have a nice flavor to them. The sauce tastes good as well. However, the sauce is runny and I cannot figure out how to thicken it. I have tried using various other combinations instead of the butter and marscapone such as half and half, heavy cream, cream cheese, and creme freche but still can't seem to get it thick.
How should I thicken the sauce or what I am doing that is preventing it from thickening?