Mushrooms, mustard and creme fraiche

This is a very simple sauce that will add flavor to any dish.

Ingredients
- Mushrooms
- Creme fraiche
- Mustard (preferably Dijon, but it's up to you)
- Olive oil or butter (or if you like you can use both)

Preparation
Cut the mushrooms in slices, not terribly thin but not thick either.
In a frying pan put the olive oil (enough to create a thin layer on the frying pan), start medium fire and then when the oil is starting to warm add the mushrooms.
After a while the mushrooms will have suck some oil, so add a little to compensate (You can skip this if you are not fond of oil or butter).
When the mushrooms are ready (they turn brown and become very soft), add the creme fraiche. Let them cook for two or three minutes, you will notice the creme fraiche starts getting "liquid".
Once the creme fraiche is semi liquid (again, this is entirely up to you there is no magic bullet here, just your personal taste), add one spoon of mustard and mix it with the creme fraiche and the mushrooms. Once everything becomes an homogeneous mix (one or two minutes after the mustard was added), turn off the fire and voila!