Pre-heat oven to 375°F
Roll out the pastry sheet and cut it into a circle about twice as wide as the wheel of brie.
The pastry must be very cold in order to work with it so, if necessary, return it to the fridge or freezer for a few minutes if it gets too warm.
Place the brie in the center of the pastry circle and cut eight evenly spaced, 1-inch slits in the crust all around the outside edge of the pastry pointing toward the center of the circle.
Top the brie with the pistachios, cranberries and honey.
Brush the edges of the pastry with the egg wash and begin bringing the flaps of pastry over the top of the brie, to the center of the cheese.
These flaps will start to overlap so that the brie becomes completely enveloped in the pastry.
At this point, you can decorate the top of the pastry with leaf shaped cut-outs of puff pastry if you desire.
Brush the entire pastry with the egg wash and chill for at least an hour before baking on a parchment lined baking sheet.
Bake for about half an hour or until the pastry is evenly golden brown.
Serve with crackers or small slices of French baguette.