
Heat the olive oil in a non-stick frying pan then add the sliced onion and cook on a medium heat until completely softened, so around 15 mins, adding a little splash of water if they start to stick at all.
Crush in the garlic and cook for a 2-3 mins further, then add the butter.
Once the butter is foaming a little, add the mushrooms and cook for around 5 mins until completely softened.
Season everything well, then tip onto a plate.
Tip the flour into a bowl with a big pinch of salt and pepper, then toss the steak in the seasoned flour.
Add the steak pieces to the pan, splashing in a little oil if the pan looks particularly dry, and fry for 3-4 mins, until well coloured.
Tip the onions and mushrooms back into the pan.
Whisk the crème fraîche, mustard and beef stock together, then pour into the pan.
Cook over a medium heat for around 5 mins.
Scatter with parsley, then serve with pappardelle or rice.

Olive Oil
1 tbls

Onions
1

Garlic
1 clove

Butter
1 tbsp

Mushrooms
250g

Beef Fillet
500g

Plain Flour
1tbsp

Creme Fraiche
150g

English Mustard
1 tbsp

Beef Stock
100ml

Parsley
Topping