The Croque Monsieur is the most fancy pants grilled ham and cheese sandwich you will ever take a fork and knife to. This impressive version of the French bar snack has crisp, buttered bread; salty-sweet ham; and velvety mornay oozing out all over the place - and it is mind-blowing.
Instead of making them one at a time over the stove, I assembled several at a time on a baking sheet, layering in the cheese sauce and ham before topping them all with more sauce and cheese. They all go under the broiler together, and that was all that is needed to meld these over-the-top ingredients together, creating a bubbly-browned top in the process.
(makes four sandwiches)