Defrost puff pastry sheets until they are soft enough to be pliable, about 20 minutes-30 minutes.
Preheat oven to 425 F.
Cut asparagus into thirds, after removing woody ends. Bring a pot of water to boiling. Add asparagus and boil for 3 minutes. Drain immediately and run cold water over the asparagus to immediately stop cooking process.
In a bowl, beat egg. Add harissa and herbs and mix well. Add ricotta, salt and Romano. Mix well and set aside.
On a lightly floured board, Roll out puff pastry. Fold in the ends to create a border. Pierce surface with a fork to dock the pastry, so it does not fill up with air. Transfer to a lightly greased cookie sheet or spray with non stick spray.
Spread ricotta filling inside. Place tomatoes and asparagus in a pattern. Sprinkle pistacchios on top.
Brush the borders with milk.
Place in oven and bake for 25 minutes until edges are golden brown.