Earlier in the day begin by seasoning on either side the Beef with salt, pepper and paprika, leave to marinate in the fridge for anywhere up to 4 hours.
Take the Beef out of the fridge up to 1/2 hour before cooking so it reaches room temp
Cut the Beef into thin strips
Gather and prepare all other ingredients
Melt 30 g of butter in a saucepan, when it starts to bubble and get hot, sear the beef on each side (you literally just want to flash cook it in the pan the middle should still be pink (do this in batches ))
Remove the Beef and set aside
In the same pan melt the rest of the butter and gently sweat (low heat ) the onions & mushrooms, season them now (pinch of salt & pepper) add Thyme if using
Turn the heat up and deglaze the pan with the Brandy
Add back in the Beef followed by the Porcini dust/ Nutmeg, Worcester sauce, Black pepper, Dijon & Sour cream
Simmer for 8/10 mins, stirring continuously.
Top with some chopped fresh flat leaf parsley & serve with either creamy mashed potatoes, rice or pasta