Ingredients:

  • 1 lb beef tenderloin, cut into 1-inch cubes
  • 2 tbsp olive oil
  • 2 tbsp Dijon mustard
  • 8 oz cremini mushrooms, finely minced
  • 1 small shallot, minced
  • 2 cloves garlic, minced
  • 1 tsp fresh thyme leaves
  • ½ tsp kosher salt
  • ½ tsp black pepper
  • 12 slices smoked turkey slices
  • 4 oz Boursin garlic and fine herbs cheese, softened
  • 1 sheet puff pastry, thawed
  • 1 large egg yolk
  • 1 tsp water
  • ¼ cup sour cream
  • 2 tbsp prepared horseradish
  • 1 tsp lemon juice
  • pinch of salt

Instructions:

  1. Preheat oven to 400°F (200°C).
  2. Heat olive oil in a skillet over high heat until shimmering. Season beef cubes with salt and pepper. Flash-sear the beef for 1–2 minutes per side until a brown crust forms, but the center remains raw. Remove from heat and let rest.
  3. While the beef is warm, brush each cube with a thin layer of Dijon mustard.
  4. In a separate pan over medium heat, sauté minced shallot and garlic until translucent. Add minced mushrooms and thyme; cook, stirring occasionally, for 8–10 minutes until all moisture has evaporated and mushrooms form a thick, dry paste. Remove from heat and let the mixture cool completely.
  5. Cut puff pastry into 12 equal squares (approximately 2½ inches). In the center of each square, place a piece of smoked turkey cut to fit the beef cube. Top the turkey with a dollop of Boursin cheese and a teaspoon of the cooled mushroom paste.
  6. Place one seared beef cube on top of the filling. Fold the corners of the pastry upward to enclose the beef, pinching the seams tightly to seal.
  7. Place the bites on a parchment-lined baking sheet. Whisk the egg yolk with 1 tsp water and brush the tops of the pastry generously.
  8. Bake for 15–20 minutes until the pastry is puffed and deep golden brown, and the internal beef temperature reaches 130°F (54°C). Let rest for 5 minutes before serving.
  9. For the optional dip, mix sour cream, prepared horseradish, lemon juice, and a pinch of salt in a small bowl until smooth.