Thaw pastry sheet at room temperature until it's easy to handle (approximately 40 min.)

Combine the walnuts and sugar in a small skillet. Cook over medium heat stirring constantly until the sugar starts to liquefy. Continue stirring constantly until the liquid reaches a golden color and coats the nuts.

Remove from heat and spread candied nuts onto a greased cookie sheet or plate and allow to cool completely. Stir occasionally as it cools to break up large pieces.

Preheat oven to 400º. Beat egg and water in a small bowl. Mix cooled walnuts and jelly together in a small bowl.

Unfold the pastry sheet on lightly floured surface. Roll sheet into a 12 inch x 16 inch rectangle. Cut 4 inch off 16 inch edged to decorate top. Spread walnuts jelly mixture in center of large square. Top with cheese.

Brush edges of pastry with egg mixture. Fold two opposite sides over cheese. Trim remaining two sides of square to 2 inches from edge of cheese. Fold sides up onto sheese and press edges to seal.Place seam-side down onto baking sheet. Decorate top with pastry scraps. Brush with egg mixture.

Bake for 20-25 minutes or until pastry is deep golden brown. Let stand for 20 minutes.