This is the must-have breakfast sandwich for all mornings!
Place 4 of the waffles on a clean work top. Spread one side of each with the mustard (if you're using it, which you totally should). Top them with ham, cheese, and the remaining waffles. Spread the top of each sandwich with 1/2 tablespoon of the butter. Melt the remaining butter in a large nonstick skillet on medium heat. Place the sandwiches in the skillet, buttered-side up, and cook 'em. Occasionally press the down with the back of a spatula to help the cheese melt. You're good to go when the waffles are golden, should take 3 to 4 minutes.