Steak in a creamy mushroom and mustard sauce

I wasn't going to post this because it's not original but then thought 'why not - after all, most of the recipes in this blog are not really original?'.
So here it is.

I used bullet steak after hearing about it on Eat Well for Less and then seeing some in Morrisons.  Half the price (ish) of the usual; steak and supposed to be just a good.  Worth a try, thought I.

Ingredients for one.
one bullet steak of a size you want!  Mine was small-ish
some oil that will stand a very hot pan
a splash of white wine (or cider, or even red, although red changed the flavour considerably)
a dollop of butter
a couple of chestnut mushrooms, sliced
some creme fraiche (I used about 2 heaped tbsps)
some dijon mustard (to own taste)
salt and pepper

Method:
Take the steak out of the fridge half an hour before so that it is at room temperature.
Get everything else ready, as this is a cook-and-serve recipe, and keep it hot.  Have two plates warming too, one for serving and one for resting the steak.

Rub oil on the steak, both sides.
Heat a frying pan to as high a temperature as you can.  Pop in the steak and f ry quickly until rare to medium rare.  Then  take out and reserve on warmed plate to rest.
In the pan put some wine and some butter (you don't need a lot).  Stir it round to deglaze the pan.  When it reaches boiling , which doesn't take long, pop in the mushrooms and cook, stirring for about 30 seconds.  Then add the creme fraiche and the mustard, salt and pepper and stir well,  If it gets too thick, add a splash of water.  Check seasonings and adjust, if necessary.
Quickly slice the steak across the grain and put it back in the pan with any juices that have gathered on the plate.  Heat to a simmer again and serve immediately.