BITE-SIZE BEEF WELLINGTONS

Steps:

• For the beef Wellingtons: Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper.
• Heat the olive oil in a large skillet over medium-high heat. Pat the beef dry with a paper towel and season all sides with 1 teaspoon kosher salt and a generous grind of black pepper. Quickly sear the beef on all sides until well browned, about 4 minutes total. Transfer to a plate to cool.
• Add the shallot to the skillet and reduce the heat to low. Cook, stirring, until softened, about 3 minutes. Add the mushrooms and 1/4 teaspoon salt and cook until the mushrooms have softened, begun to brown and released their liquid, about 5 minutes. Raise the heat to medium and cook until the liquid has evaporated, 5 to 10 minutes more. Stir in the parsley, 1/4 teaspoon salt and a generous grind of black pepper. Remove the skillet from the heat and let cool.
• On a work surface, roll 1 sheet of puff pastry into a 14-by-10-inch rectangle. Put teaspoon-sized mounds of the mushroom mixture on the pastry, evenly spacing them in 4 rows of 3. Top each mushroom mound with a piece of beef. Brush the tops of the beef with the Dijon mustard. With a sharp knife, cut the pastry into even squares around the fillings.
• In a small bowl, whisk together the cream and egg and brush all four edges of the puff pastry squares with the egg mixture. Working one at a time, pull 2 opposite corners of pastry up over each beef piece, then fold the remaining 2 corners over the top to make a packet. Seal tightly. Invert and arrange the packets seam-side down on the prepared baking sheet and press them lightly to seal the pastry. Repeat with the remaining puff pastry, mushrooms, beef, and mustard.
• Bake the Wellingtons until golden brown, 25 to 30 minutes. Remove to a serving platter and let cool at least 10 minutes before serving.
• For the horseradish cream sauce: Meanwhile, stir together the sour cream, light cream, horseradish and pepper in a small bowl. Serve alongside the beef Wellingtons.