Ham and Cheese Pinwheels

sheets frozen puff pastry, thawed overnight in the refrigerator

Dijon mustard, divided

thin slices of good-quality deli ham (about 10 ounces)

freshly grated gruyere, Swiss, fontina, sharp cheddar, or similar melty cheese (about 5 ounces)

Chopped fresh parsley, thyme, or chives (optional, for serving)