01 -
Spread out puff pastry into a rectangle about 10x12 inches on some plastic wrap.
02 -
Slather the mustard on, leaving a bit of space at the edges, then layer the ham and cheese on top.
03 -
Roll it up like a log (start with the long side), wrap in plastic, and let it chill for 20 minutes. Do the same for the other sheet.
04 -
Slice the rolled logs into 1/2-inch pieces. Bake at 375°F for about 18 minutes until golden. Add herbs once baked if you want.