If using slices from large sourdough boule like I do, cut each in half for easy handling while cooking.

Lay bread slices out on work surface. Spread dijon mustard on one side of every slice.

Add a layer of ham to half the slices, then provolone (I used an entire slice provolone, cut in half then stacked on top of one another, for each sandwich I grilled).

Top with another bread slice, mustard side down.

Add butter to a skillet or griddle and begin heating over medium heat.

Meanwhile, spread additional butter generously only onto the top surface of each prepared sandwich.

When butter in the skillet has just begun to bubble, place sandwiches, buttered side up, into pan.

Allow to cook, untouched, for 1-3 minutes, or until the bottoms are golden brown and crispy.

Flip each over and allow the other side to brown.

(I sometimes have to turn my heat down to medium-low at this point to allow plenty of time for the cheese to melt without burning the bread. Adding a little extra butter to the skillet, then swirling the sandwiches around the pan for even cooking also helps.)

Cook sandwiches in batches if needed, adding additional butter to the pan along the way.

Once all are cooked, serve immediately with Tangy Honey Mustard Dip.