Separate the egg whites from the yolks.

Finely chop the ham.

Melt the butter, then make a thick béchamel sauce by adding the milk and flour.

Add the egg yolks, ham, and cheese to the mixture. Stir to combine.

Beat the egg whites until stiff peaks form, then gently fold them into the mixture.

Grease a deep baking dish, pour in the mixture, and bake at 350°F (180°C) for 25-30 minutes.