Preheat oven to 400 degrees. Thaw puff pastry. Lay one piece on baking sheet and strech to approx 14" x 14" size.
Smooth mustard on puff pastry leaving 1" un-covered along all (4) edges. Layer with first ham, then cheese. Fold edges over to encase juices. Mix egg w/cream to creat egg wash and brush onto folded up edges.
Take second piece of puff pastry, strech to 14" x 14" sive and lay on top of first piece. Fold edges under first piece and brush top with egg wash. Crimp edges with fork and refrigerate for 1 hour.
Remove from frig, and lightly draw knife over top in a design. Do not cut all the way thru pastry. Cut vents in each corner and center.
Bake at 400 degrees for approx. 20 minutes or until top is rich mahogany color and pastry is cooked. Let rest for approx 3 minutes and cut in (6) large pieces. Serve immediatly as breakfast, lunch, or dinner entree.