01 -
Heat olive oil in a skillet over medium-high heat. Season beef cubes with salt and pepper. Sear each side for 2-3 minutes until forming a golden brown crust. Remove and allow to cool slightly.
02 -
In the same skillet, cook mushrooms, shallots, and garlic over medium heat, stirring often, until moisture evaporates and the mixture turns golden brown, about 5-7 minutes. Stir in thyme, season with salt and pepper, and set aside to cool.
03 -
Lightly dust a clean surface with flour. Roll the thawed puff pastry to approximately 1/8 inch thickness. Cut into 3-inch squares to create uniform portions.
04 -
Place a spoonful of cooled mushroom duxelles on each pastry square. Top with a seared beef cube, optionally brushing with Dijon mustard. Fold the pastry over to enclose the filling and seal edges by pressing with a fork.
05 -
Preheat oven to 400°F (200°C). Arrange bites evenly on a parchment-lined baking sheet. Brush with beaten egg to develop a glossy golden crust. Bake for 15-20 minutes until puffed and golden brown.
06 -
Allow bites to cool for a few minutes before serving warm as elegant appetizers or snacks.