Cook the mushrooms and onions in a Teflon pan with a lid. Add the garlic cloves to the pan, then add the other ingredients. Let the sauce thicken a little. You can add cream if you like.
With white mushrooms I always use white wine and light sauce thickener, with brown mushrooms I use red wine and dark sauce thickener - but that`s up to you.
If it is a main course - just serve a few croquettes or baguette with it. Focaccia also tastes delicious.