01 -
600g entrecôte steak or faux-filet.
02 -
2 tablespoons sunflower oil, divided.
03 -
One large onion, cut into thin slices.
04 -
300g of fresh mushrooms, thinly sliced.
05 -
40g of unsalted butter.
06 -
2 tablespoons of all-purpose flour.
07 -
500ml of beef stock.
08 -
A tablespoon of Dijon mustard.
09 -
150ml of crème fraîche.
10 -
Some salt and a little black pepper.
11 -
250-300g of tagliatelle or egg noodles.
12 -
Freshly chopped parsley or chives for decoration (if you'd like).