Preheat oven to 400°F. Line baking sheet with parchment paper and set aside. Beat the egg yolk and water in a small bowl with a fork, set aside.
Unfold pastry sheet on a lightly floured countertop. Using a round cookie cutter, make 9 circles.
Repeat with the other pastry sheet.
Place 9 circles on baking sheet. Place a teaspoon of lemon curd in the center of each circle. Brush around the edges with egg mixture.
Place the remaining circles on top of each circle. Press edges firmly with a fork. Make a slit in the center of each donut.
Brush the tops with egg mixture.
Bake for 13-15 minutes or until golden brown.
To make the meringue:
Whip egg whites for 1 minutes. Slowly add in sugar and continue to whip until stiff peaks. Pipe onto the top of cooled donuts. Place under broiler for 1-2 minutes.