Heat 1/2 tsp oil in a large nonstick skillet on medium-high heat until hot. Combine salt and 1/4 teaspoon pepper. Press evenly onto all surfaces of beef Tenderloin Roast. Place the roast in the skillet; brown evenly. Remove the roast from the skillet.
Heat the oven to 218°C. Place mushrooms and shallot into a food processor; pulse on and off about 10 times until finely chopped. Do not overprocess.
Heat the remaining 1/2 teaspoon oil in the same skillet over medium-high heat until hot. Add mushrooms and shallot; cook 4 to 6 minutes until tender and all liquid is evaporated, stirring often.
Add wine; cook 2 to 3 minutes until all liquid is evaporated.
Stir in mustard, thyme, remaining 1/4 teaspoon pepper. Cook 2 to 3 minutes. Remove from the skillet to a medium bowl; cool.
Line a rimmed baking sheet with aluminum foil and place it in the oven.
Unfold pastry dough on a lightly floured cutting board. Roll pastry out to a 12 by 9-inch rectangle; lay the dough with the shortest edge toward you.
Spread mushroom mixture onto pastry dough, leaving a 1/2-inch border around the edge of the dough. Place the roast in the center of the mushrooms.
Fold pastry dough neatly around the roast, stretching dough if necessary.
Cut off excess pastry dough; press to seal overlapping edges. Remove the baking sheet from the oven and dust lightly with flour.
Place pastry-wrapped roast, seam-side down, on the baking sheet. Cut 4 (2-inch) vents in the top of the pastry.
Bake in a 218°C oven for 35 to 50 minutes or until golden brown and an instant-read thermometer inserted into the center of the roast registers 57°C for medium rare; 66°C for medium.
Transfer Beef Wellington to a carving board. Let it stand for 10 minutes. (The temperature will continue to rise about 10°C to reach 63°C for medium rare; 71°C for medium.) Carve into slices and serve with your favorite vegetables.
COOKING TIPS
Mushrooms and shallot may be finely chopped by hand.
Use any excess dough to decorate Wellington.
SAFE HANDLING TIPS
Wash hands with soap and water before cooking and always after touching raw meat. Separate raw meat from other foods.
Wash all cutting boards, utensils, and dishes after touching raw meat. Do not reuse marinades used on raw foods.
Wash all produce prior to use.
Cook steaks and roasts until temperature reaches 63°C for medium rare, as measured by a meat thermometer, allowing to rest for three minutes.
Cook Ground Beef to 71°C as measured by a meat thermometer. Refrigerate leftovers promptly.