Cook Time: 35-40 minutes
2 Tbsp olive oil
1lb Beef fillet
Coarse and spicy mustard for brushing meat
1 lb Flat mushrooms (the underside shows the gills, whereas button mushrooms have no gills)
4 thin slices of prosciutto
1/2 lb Pepperidge Farms puff pastry
2 egg yolks beaten for egg wash
Large baking dish
Pre-heat oven to 400 degrees F.
On stovetop set at medium, heat two tablespoons of olive oil in a large skillet until hot. Place beef in pan and fry until browned all over. DO NOT cook the meat entirely. Simply sear the outsides to seal in all the juices. Remove from heat and brush with mustard. Cool.
While the beef is cooling, chop mushrooms and blend in food processor until smooth. Put mushroom puree in a small dry pan on stovetop. Heat moderately to high, stirring constantly until water is evaporated. When dry, remove from heat to cool. (This process takes a long time, so be patient.)
On the counter, lay out a fair amount of plastic wrap. On top of the wrap, place four slices of prosciutto that slightly overlap along the widest edges. Evenly spread the mushroom puree on top of each slice of ham.
Place the cooled beef in the center of the four pieces of ham. Tightly wrap the ham covered wrap around the beef and twist the ends to secure. Put in refrigerator for 10-15 minutes.
On a floured surface, roll out puff pastry until it will cover the beef entirely. Brush with egg wash. Take beef out of the refrigerator and remove wrap. Put beef in the center of the pastry and roll dough around the meat. Fold excess dough around the top and bottom of the meat. Cut off any excess. Brush egg wash on the top of the meat. Place in large baking dish. Put back in the refrigerator for 5 minutes.
Egg wash the top once more before placing in preheated oven. Cook for 35-40 minutes. Let cool 8-10 minutes before cutting.
Serve with boiled red potatoes and spinach if desired.