Peel the potatoes and cook them in plenty of salted water for about 15 minutes.
Meanwhile, rinse off the cauliflower and cut into small florets. Cook in salted water for 8 minutes. Then drain and drain well.
Cut the meat sausage into strips and fry them with the onion in a little oil until golden brown.
Cut the potatoes into slices and place in a large baking dish with the cauliflower, peas and meat sausage.
Melt the butter in a saucepan. Add flour and sweat lightly over medium heat while stirring. Deglaze with the milk and cream while stirring with the whisk and bring to the boil. It is spicy with salt, pepper and nutmeg.
Then pour the béchamel over the remaining ingredients in the baking dish. Sprinkle with the grated Emmentaler cheese and bake in a preheated oven at 175 degrees top / bottom heat for 15-20 minutes.