Clean the cauliflower, cut into florets and cook in salted boiling water until firm to the bite. Then drain, but keep the stock. Let cool a little, then place the florets in a baking dish.
Melt the butter in a saucepan and stir in the flour, while stirring, deglaze the cauliflower with ½ l of the stock. Cook for a few minutes while stirring. Now add the wine and season with salt, pepper and nutmeg. Pour the sauce over the cauliflower, sprinkle with Parmesan and bake in a preheated oven at 200 degrees top / bottom heat for about 12-15 minutes until golden brown.