How to Cook Beef Wellington?
Position a rack in the upper third of an oven and preheat to 400°F. Place the Beef Wellington on a greased baking sheet. Bake until the pastry is golden brown and a meat thermometer inserted into the center registers 130°F-135°F for medium rare (approx. 22-25 minutes), or 145°F for medium (approx. 25-28 minutes). Let rest 5 minutes before serving. Appliances vary; adjust accordingly.