- Preheat oven to 400°F and line a baking sheet with parchment paper. 
- Trim asparagus ends; toss with olive oil, salt, and pepper. 
- Mix cream cheese, garlic, lemon zest, and half of the Gruyère. 
- Roll puff pastry to 10x12 inches; score a 1-inch border. 
- Spread cheese mixture inside border and layer asparagus. 
- Sprinkle remaining cheeses on top. 
- Beat egg with water; brush pastry border with egg wash. 
- Bake for 20–25 minutes until golden brown and puffed. 
- Let cool 5 minutes before slicing; garnish with herbs.