what is a beef wellington?
<answer> A beef tenderloin coated with mushrooms, onions, and liver. Puff pastry encases the beef Wellington, making the outside buttery and crispy. <context> Beef Wellington. Beef Wellington is a beef tenderloin coated with mushrooms, onions, and liver. Puff pastry encases the beef Wellington, making the outside buttery and crispy. When shopping for this beef Wellington recipe, look for duck liver, chicken liver, or peppercorn mousse in specialty-food shops.1  Servings: 8.eef Wellington is a beef tenderloin coated with mushrooms, onions, and liver. Puff pastry encases the beef Wellington, making the outside buttery and crispy. When shopping for this beef Wellington recipe, look for duck liver, chicken liver, or peppercorn mousse in specialty-food shops. 1  Servings: 8.