This tart is best served the day you make it to preserve the texture. It is best served warm but can be enjoyed at room temperature. If you do have to bake it ahead of time, warm it up in a 350°F oven for about 10 minutes to crisp the pastry crust.
Make sure puff pastry is cold before baking. The cold butter will help create the layers in the pastry.
Bring the oven to temperature for at least 10 minutes before baking the crust.
If the asparagus stalks are very thick, you can cut them in half lengthwise and place them cut side down in the tart.
Par-bake the crust in the middle of the oven but bake the filled tart on the bottom rack so the crust cooks evenly.
Cool the tart on a cooling rack so the crust does not get soggy on the bottom.
Cut the tart with a serrated knife for cleaner cuts.