STEP 1
Prepare the Béchamel Sauce:
In a saucepan, melt 2 tablespoons of butter over medium heat.
Add 2 tablespoons of all-purpose flour and stir constantly to form a roux. Cook for about 2 minutes, until it’s light golden.
Gradually whisk in the milk, ensuring there are no lumps. Continue to cook and stir until the sauce thickens.
Add a pinch of nutmeg and season with salt and pepper to taste.
For a Mornay sauce, stir in some grated cheese until melted and well combined. Set aside.
STEP 2
Assemble the Sandwiches:
Preheat your HYSapientia air fryer oven to 190°C (374°F).
Spread softened butter on one side of each slice of bread.
Place the buttered side down and spread Dijon mustard (and mayonnaise, if using) on the other side.
Add 2 slices of ham and a slice of Gruyère cheese on two of the bread slices.
Place the remaining slices of bread on top, buttered side up.
Spread a layer of Béchamel sauce on top of each sandwich.
Sprinkle the grated Gruyère cheese over the Béchamel sauce.
STEP 3
Place the sandwiches in the preheated HYSapientia air fryer oven.
Cook at 190°C (374°F) for 10 minutes or until the cheese is melted and golden brown.