For scalloped cauliflower, cut cauliflower into roses and steam until tender-crisp. Cut ham into small pieces.
Melt butter in a pot, stir in flour, pour in milk, stir in eckerl cheese and let melt, remove from heat, stir in egg, season with salt, pepper and nutmeg.
Place the cauliflower in a baking dish, spread the ham on top, pour the cheese sauce over it and sprinkle with Parmesan cheese. Bake in the preheated oven at 180 °C hot air for about 20 minutes until the Parmesan has a nice color.