Preheat an oven to 200C
Heat some oil in a large pan and sear the seasoned beef all over until it’s brown.
Remove and allow to cool and brush with the mustard.
Chop the mushrooms and blend in a food processor to form a smooth puree.
Put the puree into a pdry pan and heat to evaporate the water content.
Once dry allow to cool.
Roll out a generous length of cling film and slightly overlap the ham slices.
With a pallet knife spread the mushroom mixture evenly over the ham.
Place the beef fillet in the middle and keeping a tight hold of the cling film from the outside edge, neatly roll the Parma ham and mushrooms over the beef into a tight barrel shape. Twist the ends to secure the cling film.
Refrigerate for at least 15 minutes
Roll out the pastry quite thinly to a size which will cover your beef. Unwrap the meat from the cling film.
Egg wash the edge of the pastry and place the beef in the middle.
Roll up the pastry around the beef trimming any excess.
Bake at for 35 – 40 minutes.
Leave to stand for at least 10 minutes before slicing.