Step 1: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
Step 2: Cut the Brie cheese into approximately 24 small cubes, about 1/2-inch each. Remove as much of the rind as possible, though a little is fine.
Step 3: In a small bowl, combine the chopped pistachios, chopped rosemary, sea salt, and black pepper. Mix well.
Step 4: Unroll the thawed puff pastry sheets onto a lightly floured surface. Cut each sheet into 12 squares (approximately 2.5-inch squares), for a total of 24 squares.
Step 5: Place a Brie cube in the center of each puff pastry square. Drizzle a tiny amount of honey (about 1/4 teaspoon) over each Brie cube.
Step 6: Bring the corners of the puff pastry squares up and over the Brie, pinching them together tightly at the top to form a small packet or purse. Ensure the cheese is fully enclosed to prevent leakage during baking.
Step 7: Dip the top of each sealed Brie bite into the egg wash, then immediately press the egg-washed top into the pistachio mixture, ensuring a good coating.
Step 8: Arrange the coated Brie bites seam-side down on the prepared baking sheet, leaving a little space between each.
Step 9: Bake for 15-18 minutes, or until the puff pastry is golden brown and puffed, and the Brie cheese is melted and gooey. Keep an eye on them to prevent burning the pistachios.
Step 10: Carefully remove from the oven and let cool for a few minutes on the baking sheet before transferring to a serving platter. Garnish with fresh cranberries or pomegranate seeds, if desired, and serve warm.