This one requires a bit of effort, but it’s well worth it!
First I seal a piece of beef fillet (about 1 kilo) in olive oil. When it’s cold, I season it and spread Dijon mustard all over it. I cook mushrooms cut up into small pieces in a dry non-stick pan, seasoning towards the end of the cooking process. I lay strips of Parma ham on a sheet of cling film and arrange the mushrooms on top. I place the fillet in the centre and with the aid of the cling film, roll up tight. This goes into the fridge for half an hour. I roll out puff pastry and lay it on another sheet of cling film, unwrap the meat and lay it on the pastry. Again with the aid of the film, I roll up tight making sure the meat is well covered. Back in the fridge for half an hour. I finally eggwash the pastry and make cuts across the roll. It cooks for 30-35 minutes at 180°C. It’s best if you stand the meat on a rack in the roasting tin.
The meat should be pink, but if you prefer you can cover the pastry with some foil and continue to cook for 10-15 minutes.