1 sheet frozen puff pastry (from a 17.3 ounce package), thawed
1 pound asparagus, trimmed to fit pastry
1 cup shredded Gruyere cheese
1 cup shredded Emmentaler cheese
1/4 cup shredded Parmesan cheese
1 tablespoon olive oil
salt & pepper
Preheat oven to 400*F. Line a large rimmed baking sheet with parchment.
Roll out puff pastry on a floured board to a 16x10 inch rectangle; trim uneven edges with a sharp knife or bench scraper. Transfer to prepared baking sheet. With a sharp knife, score a border 1 inch in from the edge of the dough. With a fork, prick the dough all over inside of that scored border. Bake until golden, 10-15 minutes.
Lightly brush the inside portion of the tart with half the olive oil. Sprinkle with gruyere and emmentaler inside the border, then arrange asparagus spears on pastry, alternating ends and tips. Brush asparagus with remaining olive oil, then season lightly with salt and pepper. Sprinkle with parmesan.
Bake until cheese is melted and asparagus is tender, about 15-20 minutes.
adapted from Great Food Fast