Season meat with salt and pepper. In a heavy frypan quickly sear fillets on both sides. Turn heat to low; add butter, shallots, mushrooms and wine to pan. Cook and stir until all liquid is gone and mixture is very soft.
Spread 1 tablespoon pate over each fillet; then spread and pat 1/4 cup of mushroom mixture over pate. Carefully wrap each mushroom topped fillet in pastry, rolling pastry to stretch as needed. Pinch edges to seal. Brush with beaten egg yolk. Bake in 450 degree oven for 15 minutes. Makes 4 servings.
