Quick Croque-Monsieur Sandwich (Air Fryer)

The Croque-Monsieur is a beloved French staple—a toasted ham and cheese sandwich elevated with a luxurious layer of cheesy béchamel. This French classic offers a delightful lunch quickly made in the air fryer.

The Cheesy Bechamel

This sandwich stands out because of its smooth and irresistible topping, made of bechamel sauce called Mornay sauce, with extra cheese melted into it. Unlike simply grilling cheese on top of a sandwich, which is greasy and stringy, this thick sauce will form a gratin layer but keep its smooth and creamy texture, which is simply addictive. A welcomed touch of nutmeg to top it all elevated this simple dish to another level!

The Technique

Making béchamel sauce is easier than it seems—remember the trick of “warm meets cold” to prevent lumps. Professionals often pre-make a cold roux (flour and butter) and store it in the refrigerator, adding it to hot liquids later to thicken sauces seamlessly. But here, we’ll reverse it: Make a warm roux, then add cold milk while whisking. This way, you’ll get a perfectly smooth béchamel every time!

Cheeses

If you want to make a French sandwich, you could use Comté, Emmental, or Gruyère cheese. Nowadays, everything is permitted, I’ve used simple pre-cut slices of Harvarti on the inside and Comté on top. But a good cheddar would do, too, although I would use a sharp, slightly aged cheese. In France, nowadays, pretty much all sandwiches are called croque-monsieur sandwiches, could be made with tuna, veggies, chicken, etc. made with or without the gratin topping. Today’s version is the traditional one you’ll find in most French Bistros.

Bread and Ham

The bread choice is usually a square-shaped bread, “pain de mie,” as it is called in France. This basic bread is sliced thinly and has a thin crust. But if you want to elevate your sandwich, you can always use lovely sourdough bread.

As for the choice of ham, it is the best cooked white ham you can find; basically, you can get creative here.

Air Frying to the Rescue

Using an air fryer to make a Croque-Monsieur is genius because it streamlines the cooking process, delivering that golden gratin and gooey interior in minutes. The air fryer’s rapid convection heating evenly toasts the bread and melts the cheese without requiring flipping or preheating larger appliances. This approach reduces cooking time and achieves a perfect, bistro-style gratin finish on top. It’s ideal for grilling any sandwich on a busy day.