Preheat your oven to 400°F (200°C).
In a medium-sized mixing bowl, combine the softened cream cheese, shredded cheese blend, chopped herbs, garlic powder, salt, and pepper. Mix until smooth and well incorporated.
On a floured surface, roll out your thawed puff pastry sheet until it's slightly larger than its original size. Cut the pastry into 3-inch squares.
Place about a tablespoon of the cheese mixture in the center of each square of pastry. Fold the corners towards the center to create triangles, pressing down gently to seal them closed with a fork.
Arrange the sealed pastry bites on a baking sheet lined with parchment paper. Brush the tops with beaten egg. Bake for 15-20 minutes or until they are puffed up and beautifully golden brown.