•3 tbsp. butter, divided
•1/3 cup minced shallot or red onion
•1-1/2 cups coarsely chopped mushrooms
•1/4 cup red wine
•2 beef tenderloin steaks — 4 oz. each, cut 1 inch thick
•1/2 pkg. frozen puff pastry dough, thawed
•1 tbsp. water
1.Melt 2 tbsp of the butter in a heavy skillet over medium heat. Add the minced shallots and cook, stirring, about 2 minutes. Add the mushrooms and continue to cook, stirring frequently, until mushrooms have started to brown. Add the wine and cook, stirring until evaporated. Season with salt and pepper and transfer to a bowl.
2.Add the remaining 1 tbsp of butter to the skillet and increase to high heat. Add steaks to pan and sear both sides until browned, about 1 minute per side. Remove steaks from pan immediately. Let cool.
3.On a lightly floured surface, roll the block of puff pastry dough out to a 12-inch square. Cut the square in half, then cut one of two halves in half again (reserve the remaining half of the dough).
4.Beat together the egg and water and brush lightly over the surface of the two small squares of dough. On each square, spoon half of the mushroom mixture and top with one steak. Pull the corners of the dough up and over and seal up any openings by pinching and folding them together. Turn over and arrange on a baking pan. Brush with egg mixture.
5.Using a heart-shaped cookie cutter, cut shapes out of the reserved pastry dough to decorate the top of each packet and brush with egg wash.
6.Preheat the oven to 425
7.Place Wellingtons in the oven and bake for 15 to 20 minutes or until puffed and golden. Let stand for about 5 minutes before serving.