Step 1

Heat the oven to 400 degrees F. Beat the egg and water in a small bowl with a fork or whisk.

Step 2

Stir the muenster cheese, parmesan cheese, onion and garlic powder in a medium bowl.

Step 3

Unfold the pastry sheet on a lightly floured surface. Brush the pastry sheet with the egg mixture. Top with the cheese mixture and spinach. Starting with a short side, roll up like a jelly roll. Cut into 20 (1/2-inch) slices. Place the slices, cut-side down, onto baking sheets. Brush the slices with the egg mixture.

Step 4

Bake for 15 minutes or until the pastries are golden brown. Remove the pastries from the baking sheets and let cool on wire racks for 10 minutes.