Emeril's Late Night Ham and Cheese
Heat a large skillet.
Spread the mustard on 1 side of the bread slices. Add the oil to the skillet and place 4 bread slices mustard side up. Top the bread slices with the cheese slices, the ham, and then the tomato slices. Arrange the last 4 bread slices, mustard side down, on each stack to make sandwiches. Press the sandwiches with a spatula until brown and crisp. Flip the sandwiches and press again, until brown and crispy.
Remove sandwiches from the skillet, cut in half diagonally and serve immediately.