Heat the clarified butter in a pan. Sweat the onions in it while stirring with the bacon until light brown. Add the cabbage, stir-fry for about 10-15 minutes, then remove.
Wipe out the pan. Melt the butter in it and fry the spaetzle until golden brown. Add the cabbage mixture, heat, season with salt, pepper and freshly grated nutmeg. Sprinkle with Gruyère and parsley.