Set out your puff pastry to thaw and your cream cheese to soften.
Line a baking sheet with sides with parchment paper.
Measure and prep all ingredients.
Preheat your oven to 400°.
Sprinkle each salmon fillet (that has been deboned and skinned) with salt and pepper. Set aside.
In a skillet, melt butter and then add in green onion and garlic and saute' for a few minutes.
Stir in lemon juice and cream cheese until melted and mixed.
Add bread crumbs and Parmesan cheese to the mixture and then top with spinach.
Saute' until the spinach softens, mixing all ingredients together. Set aside to cool.
Roll out both puff pastry sheets into 2 - 10" x 14" rectangles on a lightly floured surface. Cut each pastry sheet in half.
Add one salmon fillet to the center of each puff pastry rectangle.
Top each fillet with 1/4 of the spinach mixture.NOTE: If you want the filling on the top of the salmon after baking, simply add a rectangle of the spinach mixture under each salmon fillet. Whisk the egg for egg wash and use a pastry brush to brush egg wash around the edge of the rectangle.
Carefully fold the puff pastry over the salmon and press the edges together to form a seal. Add more egg wash to the ends of the puff pastry and fold over the top of the wrap and press to seal.
Transfer your Salmon Wellingtons to the baking sheet with folded sides on the bottom.
Use a sharp knife to make cross hatch marks across the top of pastry to allow steam to escape while they are baking to prevent sogginess.
Brush the tops of each pastry with more egg wash to give a golden color while baking.
Bake in a preheated oven for 25-30 minutes until puff pastry is golden and an internal temperature is 145°.
Remove the Wellingtons from the oven for a few minutes before slicing and serving.