How to make it

1. https://www.youtube.com/watch?v=XXUsFeQqsZc
2. Béchamel sauce: Melt butter in a medium saucepan over medium heat. Whisk in flour and cook, stirring constantly, for about 3 minutes. Gradually add milk, stirring well until the mixture is smooth. Cook, stirring, until sauce is thickened. 
3. Season with a little bit of salt and pepper. Remove from heat and whisk in mustard, Lee Kum Kee Sriracha Mayo Dressing/ Spread (Cage-Free Eggs) and nutmeg. Set aside while you make the sandwiches. Assemble sandwiches: Preheat oven to 425° F. Line a baking tray with parchment paper and set aside.
4. Spread each bread slice with a layer of béchamel, spreading to completely cover the slice of bread. Place 4 slices of bread, béchamel side up, on the prepared baking sheet. Place a piece of ham on top, a handful of Gruyere cheese, and then a sprinkle of parmesan cheese. Place remaining slices of bread on top, béchamel side up, then top with remaining gruyere and parmesan cheese.
5. Bake at 425° F for about 5-6 minutes, until cheese is melted, and then turn the oven to broil and broil until the cheese on top is lightly golden, 2-4 minutes. Serve with additional Lee Kum Kee Sriracha Mayo Dressing/ Spread (Cage-Free Eggs) if desired. Enjoy!