Thaw pastry sheet at room temperature 30 minutes. Preheat oven to 400°F.

Mix egg and water. Unfold pastry on lightly floured surface. Roll into 14" square. Cut off corners to make a circle. Spread preserves and sprinkle almonds in center of circle, if using. Top with cheese. Brush edge of circle with egg mixture. Fold two opposite sides over cheese. Trim remaining two sides to 2" from edge of cheese. Fold these two sides onto the round. Press edges to seal. Place on baking sheet, seam-side down. Decorate top with pastry scraps, if desired. Brush with egg mixture.

Bake 20 minutes, or until golden. Let stand 1 hour before serving.