4 skinless salmon fillets (approx. 6 oz / 170g each, about 1-inch thick)
1 sheet puff pastry, thawed (approx. 9–10 oz / 250–280g)
4 oz (115g) cream cheese, softened
2 cups (60g) fresh baby spinach, finely chopped
2 cloves garlic, minced
2 tbsp grated Parmesan cheese
1 tsp lemon zest
1/2 tsp sea salt
1/4 tsp freshly ground black pepper
1 large egg + 1 tbsp water (whisked together for egg wash)