Remove your beef roast from the refrigerator and allow to come to room temperature.

Pre-heat your oven to 425oF

Chop your mushrooms and finely dice the shallot and garlic cloves

Saute the mushrooms and shallots butter and olive oil on medium-low heat until they begin to soften. Add the garlic and chives and cook until the mixture is completely soft and beginning to brown.

In a large skillet over high heat, brown your roast on all sides with a tablespoon of olive oil. You’re trying to develop the Maillard reaction on the outside of the roast, not cook it fully. 

When all sides are browned, remove from the hot pan and allow to cool for 5-7 minutes. 

On a floured surface, roll out your puff pastry to a large rectangle, big enough to cover your roast completely.

Beat your egg thoroughly, and set aside while you prepare the Wellington.

Using a spoon, spread out the duck pate on the pastry in a rectangle to cover the roast.

Spread your mushroom mixture on top of the pate.

Place the roast, upside down on top of the pate and mushroom mixture, and begin to fold over the edges of the pastry to cover the roast.  Use your fingers and a little water to crimp the pastry.  Use a knife to trim off the excess pastry on the ends.

Roll out the excess pastry and cut out three leaves or other decorative elements to place on top of your Wellington.

Brush the fully assembled Wellington with egg wash. 

Bake in a 425oF oven for 35-45 minutes depending on the size of your roast. Your Roast is fully cooked when the pastry is golden brown and delicious and the beef has reached an internal temperature of 135oF. 

Remove from the oven and allow to rest for 10-15 minutes before slicing to serve.