Sauté the aromatics by heating olive oil in a skillet over medium heat. Add finely chopped shallots and sauté for about 3-5 minutes until translucent.

Prepare the duxelles by adding minced garlic and then finely chopped cremini mushrooms. Cook for about 10-15 minutes until browned.

Add dry white wine, scrape the bottom of the skillet, and let it simmer until mostly evaporated.

Mix in fresh thyme and heavy cream, season with salt and pepper, and simmer gently until thickened. Let cool.

Pat the salmon fillet dry, season with salt and pepper, and spread Dijon mustard over the top.

Preheat the oven to 400°F (200°C). Flour your countertop and roll out the pastry sheets.

Assemble the Wellington by placing the salmon in the center of the pastry, spreading cooled duxelles over it, covering with another sheet of pastry, sealing, and scoring the top.

Apply egg wash on the pastry and chill in the fridge for 30 minutes.

Bake the chilled Salmon Wellington for 30-40 minutes until golden brown and internal temperature reaches 145°F (63°C).

Let it rest for about 10 minutes before slicing, garnishing with parsley and lemon wedges.