Preheat the oven to 400°F/205°C.
Line a baking sheet with parchment paper and set aside.
Fill a large bowl with ice water. In a large skillet, bring 2 inches (5cm) of water to a boil. Add in the asparagus and cook until bright green and tender crisp, 2 to 3 minutes. Remove the asparagus and transfer to the ice bath to stop the cooking. Once cooled, drain and pat dry. Set aside.
On a floured surface, roll out puff pastry to a 12 inch (30cm) square. Transfer to the parchment lined baking sheet. With a sharp knife, lightly score pastry dough 1 inch (2.5cm) in from the edge. Roll the edges to the cut line to form a crust-like border. Using a fork, pierce the dough inside the border. Chill in the refrigerator for 15 minutes. Remove and brush the entire surface with the egg wash.
Bake until lightly golden, about 10 minutes. Remove from the oven to cool for 5 minutes. Then brush the bottom of the tart shell with mustard. Sprinkle with the Emmental cheese and lay the asparagus on top alternating head to toe. Sprinkle the top with Parmesan cheese and brush the pastry border with the remaining egg wash. Bake for 15-20 minutes until the crust turns golden brown and puffy.
Let cool 5 minutes before slicing to serve.
Preheat the oven to 400°F/205°C.
Line a baking sheet with parchment paper and set aside.
Fill a large bowl with ice water. In a large skillet, bring 2 inches (5cm) of water to a boil. Add in the asparagus and cook until bright green and tender crisp, 2 to 3 minutes. Remove the asparagus and transfer to the ice bath to stop the cooking. Once cooled, drain and pat dry. Set aside.
On a floured surface, roll out puff pastry to a 12 inch (30cm) square. Transfer to the parchment lined baking sheet. With a sharp knife, lightly score pastry dough 1 inch (2.5cm) in from the edge. Roll the edges to the cut line to form a crust-like border. Using a fork, pierce the dough inside the border. Chill in the refrigerator for 15 minutes. Remove and brush the entire surface with the egg wash.
Bake until lightly golden, about 10 minutes. Remove from the oven to cool for 5 minutes. Then brush the bottom of the tart shell with mustard. Sprinkle with the Emmental cheese and lay the asparagus on top alternating head to toe. Sprinkle the top with Parmesan cheese and brush the pastry border with the remaining egg wash. Bake for 15-20 minutes until the crust turns golden brown and puffy.
Let cool 5 minutes before slicing to serve.
