Preheat the oven to 400 degrees, and adjust the oven rack to middle position. Line a rimmed baking sheet or pie pan with parchment.
Dust a work surface with small amount of flour. Carefully unwrap the puff pastry and place it on the work surface. Dust a rolling pin with flour and lightly roll the pastry into an 11-inch square. The pastry is already rolled out, so you won't have to do much, plus it's okay to estimate this without measuring. If any tears happen, just press them together with your fingertips.
Place the brie round in the center of the pastry. Gently spread the preserves over the top of the cheese. Wrap the pastry around the brie, folding the corners over the top to form a neat package. Using your hands, press the pastry around the edges of the cheese to neaten the top and sides.
Place the wrapped brie onto the baking sheet or pie plate. If the pastry is warm and soft, chill in the refrigerator for 10 to 15 minutes, or until you're ready to bake and serve.
Just before baking, brush the beaten egg all over the top and sides of the pastry. Try not to let the raw egg pool around the sides. Bake at 400 degrees until the pastry is deep golden brown, 35-40 minutes.
Remove from the oven and allow to cool for 10 minutes before serving. Transfer to serving platter. Spoon or squeeze out the roasted garlic cloves around the edge of the brie and serve while warm with bread, crackers, or fruit.