Thaw Puff Pastry: Let it thaw on the counter for 20 minutes to 1 hour.
Preheat Oven: Set to 425°F.
Prepare Cream Cheese Mixture: In a bowl, mix cream cheese, dill, lemon zest, lemon juice, and mustard until smooth. Set aside.
Prepare Pastry: Lightly flour a surface, roll out puff pastry to 18-20 inches long, and cut in half. Each half should be about 3 times the width of a salmon piece. One sheet should cover 4 salmon pieces. Assemble each sheet fully before rolling out the next.
Assemble: Place a generous spoonful of cream cheese mixture in the center of each pastry piece, spread to match salmon size. Place salmon on the cream cheese, top down.
Seal Pastry: Fold long sides over salmon, brush with egg wash to seal. Repeat with short sides, trim excess, and fold ends over. Flip the pastry over.
Bake: Place on a parchment-lined baking sheet. Brush with egg wash, make slits on top, and optionally sprinkle with Maldon salt. Bake for 20-30 minutes until golden brown.
Enjoy immediately!
