Finely chop the onion.
Finely chop the mushrooms (half cm in size)
Heat the oil or butter in a medium sized saucepan (if you choose to use butter, place afew drops of oil so that butter does not burn)
Place the onion in the pan and fry until it becomes transparent.
Add the mushrooms and cook, stirring until the mushrooms draws all the juices and shrink.
Shake the cream containers and then add to the pan.
Add salt, pepper and nutmeg to taste and then mix.
Bring everything as close to a boil as possible (just enough for it to be bubbling)
Reduce the heat to a minimum and cook for about 10 minutes until the sauce is reduced by atleast a third in amount.
Serve over fettucini pasta or even oysters!
Bon Appetit!