Beef Wellington

A 5-lb whole fillet of beef, well trimmed of excess fat and sinew (silver skin)
1 shallot, finely chopped
3 Tbs butter
1 lb mushrooms, very finely chopped
A grating of fresh nutmeg
Salt and freshly ground pepper to taste
2 large sheets puff pastry
8 oz prepared pate de foie
1 egg yolk mixed with 1 Tbs water

Place the fillet on a wire rack in a large roasting pan and roast in a preheated 425F oven until it reaches an internal temperature of 120F, about 20 minutes. 

Remove from the oven and let the meat return to room temperature. 

Meanwhile, saute the shallot in the butter until tender but not browned, about 5 minutes. 
Add the chopped mushrooms and saute over high heat, stirring frequently, until almost all of the moisture has evaporated - the mixture should resemble a coarse paste. 
Season with nutmeg, salt, and pepper, and allow to cool to room temperature. 

To assemble, roll out the sheets of puff pastry until they are about 2 inches longer and wider than the fillet.
Place the fillet in the center of one of the sheets of puff pastry and spread the pate de foie in a thin layer over the top and sides of the beef. 
Top with the mushroom mixture. 
Brush the edges of the pastry with water and place the second sheet of puff pastry over the top.
Trim and seal the edges, crimping with your fingers or the tines of a fork. 
Decorate the top of the log with any remaining puff pastry cut into decorative shapes and brush with the egg yolk mixture. 

Bake in a preheated 425F oven for 10 minutes. 
Reduce the heat to 375F and bake until the crust is golden brown, about 20 minutes. Remove from the oven and allow to rest 10 minutes. 

To serve, cut with a very sharp knife into slices about 3/4 inch thick. 

Serves 8 to 12.