1/2 (17.3-ounce) package (1 sheet) frozen puff pastry sheets, thawed
1 tablespoon water
1 teaspoon poppy seed
1/2 cup finely chopped deli ham
1/4 cup mayonnaise
1 teaspoon Dijon-style mustard
2 tablespoons chopped green onions
Heat oven to 400°F.
Place waxed paper onto cutting board; unfold 1 pastry sheet on waxed paper. Using a pizza cutter or knife, cut pastry sheet into 1 1/2-inch squares. Place squares onto ungreased baking sheet. Repeat with remaining pastry sheet.
Combine egg and water in bowl. Brush tops of pastry squares; sprinkle with poppy seed. Bake 8-10 minutes or until pastry is puffed and golden brown. Cool completely.
Combine all filling ingredients in bowl. Split each square horizontally with small serrated knife. Fill with about 1 teaspoon filling mixture.
Puff pastry squares can be baked ahead. Store in container with tight-fitting lid up to 2 days or freeze up to 2 weeks. Reheat at 350°F, 5 minutes.