(I feel like I've been using a lot of frozen puff pastry lately, which is a little embarrassing, since I know how to make it myself. When I'm home with proper cooking tools, I'll post a recipe for homemade Pâte Feuilletée.) In this particular dish, the mild fontina cheese mellows out the saltiness of the prosciutto and complements the sweet nuttiness of the asparagus.
For one (approximately 11 inches x 11 inches) tart, you'll need:
+ one sheet of frozen puff pastry, thawed
+ one bundle of fresh asparagus (the thinner, the better)
+ fontina cheese, grated, 1/2 cup
+ prosciutto, about 7 sheets
+ olive oil, 2 teaspoon
+ balsamic vinegar, 5 tablespoons
Preheat the oven to 375 degrees F. Remove the woody ends from the asparagus, and slice the remaining portion into 1 inch pieces. Cut the prosciutto into thick ribbons (see this page on how to chiffonade).
Evenly spread 2 tablespoons of the cheese directly onto the pastry. Add the asparagus; drizzle with olive oil and lightly salt and pepper. Add the prosciutto and remaining cheese. Add a bit more pepper (you probably won't need any salt, because of the prosciutto), and slide it into the oven for about 20 minutes, or until the cheese is melted and the pastry golden brown.
While the tart is baking, reduce the balsamic vinegar by half. When you remove the tart from the oven, drizzle the reduction on top. Enjoy!