preheat oven to 400°. Using a rolling pin, roll pastry into four pieces, each about 5 x 8". Transfer two pieces to a large baking sheet lined with parchment paper. Remove skin from salmon and place a fillet in center of each of those pieces.
In a small bowl, mix parsley, basil, and butter. Stir until herbs are thoroughly mixed in. Season with salt and pepper. Spread butter mixture on top of salmon.
Dip a pastry brush into beaten egg and let excess run off. Brush edges of pastry around salmon with egg. Cover each piece with remaining puff pastry. Pinch pastry together firmly to seal, then lightly press tines of a dinner fork along edges for a decorative effect. Brush top of pastry with remaining egg.
With a sharp knife, cut two small slits into top of each pastry so steam can escape during baking. Bake for 20 minutes or until pastry has risen and is crisp and Golden.