In a skillet, heat olive oil over medium heat. Add minced garlic and sauté for about 1 minute until fragrant.
Add chopped spinach to the skillet and cook until wilted, about 2-3 minutes. Season with salt and pepper. Remove from heat and let cool slightly.
In a mixing bowl, combine the wilted spinach, cream cheese, feta cheese, and lemon zest. Mix well until thoroughly combined.
Roll out one sheet of puff pastry on a lightly floured surface into a large rectangle. Place the salmon fillet in the center of the pastry.
Spread the cheese and spinach mixture evenly over the top of the salmon.
Fold the sides of the puff pastry over the salmon, sealing the ends tightly to create a sealed parcel. Use the second sheet of pastry if desired to reinforce the structure.
Place the wrapped salmon onto a baking sheet lined with parchment paper. Brush the top with the beaten egg for a golden finish.
Bake in the preheated oven for 25-30 minutes or until the pastry is puffed and golden brown.
Allow the Wellington to rest for 5 minutes before slicing and serving.
Notes
Serve with mixed greens and a light lemon vinaigrette for an elevated touch.