Baked salmon in puff pastry with mushroom duxelle

Preparation

• Chop the mushrooms in a food processor, by pulsing them a few times. Melt butter in a sauté pan over medium heat. Add shallots and sauté until soft.
  Stir in cremini mushrooms and simmer for 7-10 minutes, stirring occasionally, allowing the mushrooms to cook down while their moisture evaporates.
• 
  Add white wine, thyme and salt. Simmer for an additional 5-7 minutes.
  Remove from heat and stir in whipping cream. Use immediately or cover and refrigerate.
• 
  For Salmon Wellington:
  Cut puff pastry into four equal 5" x 8" (13cm x 20cm) sheets. Approximate measurements are suitable.
  Spread ¼ cup mushroom duxelle evenly onto each sheet of puff pastry, leaving a ½" (1 cm) margin at the edges. Place a salmon fillet in the center of each prepared pastry, seasoning each with a sprinkle of salt.
• Cut the filets closer to 8 ounces. Brush an egg wash (beaten egg with water) over each pastry and baked this at 400 degrees F for 15 minutes. Next, lower the heat to 325 degrees F and bake for an additional 15-20 minutes until puff-pastry is flaky and golden brown.
• Make Beurre Blanc Sauce to drizzle around each pastry.