In a small bowl whisk together the ricotta, Parmesan, lemon zest, herbs and salt and pepper.
Flour your work surface and roll out puff pastry, keeping the square shape. Fold the sides over about 1/2 inch to form a border. Spread cheese mixture inside the border. Lay the asparagus on top of the cheese mixture. Brush edges of pastry with egg wash. Drizzle the top with olive oil and bake for 20 minutes.