Thaw Brussels sprouts and cut in half. Dice and sauté the onions. Add the diced Kasseler and fry. Add Brussels sprouts and toss briefly. Put everything in a greased baking dish.
Whipped cream and milk with eggs. Season to taste with spices (try). Add the flour and parmesan. Mix well and pour over the ingredients in the baking dish.
Bake at 180 - 200 ° C in a preheated oven for 35 minutes. Then let it rest briefly.