Saute your onions until they are transparent and tender to produce the foundation of the sauce
Take your time doing this task. When adding onions, make sure they are cooked all the way through
Cook over low heat to prevent scorching of the garlic
It will give the sauce a bitter taste if you don't
Cook until the mushroom takes on a brown color
An additional method to enhance its flavor
To thicken the sauce, stir together flour and the remaining olive oil in the pan after the onions and vegetables have browned
After deglazing the pan with sweet Marsala wine
Let it bubble until it reduces in size
Finally, drizzle in a little cream over a low heat
