Heat half oil and butter in a fry pan, sear off prociutto wrapped beef fillet. Once seared off let rest on some paper towel to take off excess moisture.
Wipe out fry pan, start with fresh oil and butter and heat. Infuse garlic and sutee mushrooms add a tspn chopped thyme leaves to mushrooms,allow thyme to infuse, let rest and cool.
Lay out one sheet of pastry and place dry fillet on pastry, top with mustard and mushroom combo making sure you dont have any juices. Lay second sheet over fillet and make sure you brush folded pastry with whipped egg wash. Fold ends of pastry to make a parcel.
Brush pastry with egg wash and pre heat your oven to 180 degrees celsius.
Place parcel on a grease proof tray or use some baking paper to stop the parcel from sticking to tray. Bake in a 180 degrees oven for approx. 40 mins or 55 mins depending on how well done you prefer you meat.
Once cooked rest for 10 minutes.
Slice fillet into 4 serves. Serve with steamed vegetables.