Preheat your oven to 350°F (175°C).

Cut brie into twelve 1½ inch cubes and pat dry.

Roll out puff pastry to ¼ inch thickness and cut into twelve 3-inch squares.

Mix chopped pistachios, thyme, and sea salt in a shallow bowl.

Assemble each bite by placing a brie cube in the center of a pastry square and folding it over; brush with egg wash and roll in pistachio mixture.

Place on a baking sheet and bake for 15-20 minutes until golden brown.

Let cool for 3-4 minutes before serving. Optionally, sprinkle black pepper on top.