Start by preparing the chopped mushroom mixture (duxelles). Finely chop the mushrooms, fry them in a little butter and then stir in the finely chopped shallot, crushed garlic and chopped chives. Season with salt and black pepper and then leave to cool.
Blanch the spinach leaves and refresh in iced water. Drain to remove the water.
Using a really hot frying pan, sear the roast beef and leave it to rest for 10 minutes. Wipe off any excess fat.
Roll out the puff pastry sheets and arrange the dry spinach leaves on top, next spread the mushroom duxelles over the spinach leaves and finally place the roast beef on top.
Roll the pastry up to make a sort of ballotine and brush it all over with the egg wash. To get the beef medium rare, cook it in a preheated oven at 175*C for 25 – 30 minutes.
Serve the beef wellington with seasonal vegetables, a gratin dauphinois and a light veal gravy made with black truffle breakings.
Enjoy your meal!