Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a skillet, heat olive oil and sauté chopped onion until translucent (3-5 minutes). Add minced garlic for 1 minute, then stir in the fresh spinach until wilted.

Remove from heat, let cool slightly, then combine with cream cheese and dill. Season with salt and pepper.

Pat salmon fillets dry and season with salt and pepper on both sides.

Roll out puff pastry to ¼ inch thick, cut into four equal squares.

Scoop spinach mixture into each pastry square, top with a salmon fillet, fold pastry over, and pinch edges to seal.

Score slits in the top of each Wellington for steam to escape and brush with beaten egg.

Bake for 20-25 minutes until pastry is golden brown. Check salmon temperature reaches 145°F (63°C).

Let rest for 5 minutes before serving with lemon wedges.