Last night I attempted one of my French bistro sandwiches, the simply elegant Croque Monsieur. It’s a fancy sounding name for an elevated ham and cheese sandwich, but once you bite into one, you have to call it by name.
Assembled open faced, finished in the oven, including the broiler should you dare.
I cannot recommend exact quantities on this, as I feel you just assemble and make it look pretty. The quick bechamel I made was probably enough for two sandwiches, so I will go into a bit more detail with the sauce.
For the sandwich, I used two medium-thick slices of semolina bread, but any heart sliced bread or baguette will do – Italian, French, you could even go rye, though I prefer a milder tasting bread. I spread a thin layer of super grainy mustard and topped with ham. I then preheated my oven to 400 degrees and got started on the bechamel.
This was not a true bechamel. Instead a made a roux by melting two tablespoons butter and whisked in two tablespoons of flour. When the roux was cooked to a light blond color I added more grain mustard, a pinch of garlic powder (I would have preferred onion powder but I was out), a few dashes of nutmeg, salt and pepper. While whisking over low heat, I added 2/3 cup milk, added slightly more, thinning the sauce a bit more. You want the consistency to fall somewhere between mayo and gravy – thinner than mayo, but not so thin that it drips everywhere. I then added about two heaping tablespoons of Parmesan cheese and a teaspoon of Colman’s mustard powder.
I removed the sauce from heat and continued to assemble the sandwich. I spread about half the sauce I made over the ham on each slice.
I topped the sauce with Swiss cheese (you may also use Gruyere), and placed my sandwich in the oven.
I baked it for about 5 minutes, then switched on the broiler to melt the cheese even more for another two minutes. The result? Heaven.