Asparagus Gruyere Tart

• asparagus↗2 lbs

  trimmed

• puff pastry, all-butter, thawed↗1

  (450 g) package

• Dijon mustard↗2 tablespoons
• gruyere cheese↗1 1⁄2 cups

  shredded

• black pepper↗1⁄2 teaspoon

  freshly ground

• egg↗1
• milk↗1 tablespoon

Step-by-step instructions

1. 1

   Line 2 baking sheets with parchment paper or grease well.

2. 2

   Steam asparagus in a steamer or on a rack in a skillet until tender-crisp, takes about 3 minutes.

3. 3

   Immediately remove from pan and chill in cold water to stop cooking; pat dry and set aside.

4. 4

   Roll out each pastry sheet to fit the baking sheet, place on prepared pans.

5. 5

   Spread evenly with mustard, leaving 1 inch border around the edges.

6. 6

   Arrange asparagus, side by side and alternating ends, on the mustard; sprinkle with cheese and pepper.

7. 7

   In a small bowl, beat egg with milk; lightly brush over the pastry border.

8. 8

   Bake in oven, rotating pans halfway through, until puffed and golden. Cheese should be bubbly in about 18 minutes.

9. 9

   To serve: cut each tart into 6 pieces, serve warm or cold.