I made this recipe for a friend's 40th birthday party a year ago, and I remember it being such a hit that I decided to make it again for a White Elephant Christmas party. I think Ina Garten hit the nail on the head with this appetizer. I love me a ham and cheese sandwich, but adding puff pastry to the mix just takes this rather plain sandwich to another level. Also, substituting gruyere cheese in place of swiss cheese makes it even fancier. And, using Dijon mustard instead of plain ol' yellow mustard takes it to gourmet status. Plus, it's super simple to make and tastes yummy! Really. Give this fancy version of the plain ol' ham and cheese a try and you will want to make it for your next party! Enjoy!