Grate the flour and margarine until crumbly, add water and salt and combine to form a dough (do not knead). Cover and put in a cool place. When the dough is really cool, roll out and place in the tray.
Cut the onions into slices and sauté them in oil - remove and allow to cool
Fry the bacon cubes in the same pan, remove them and let them cool down
Spread the onions and diced bacon on the dough that has been dished
Spread the pouring over it
Bake the Schaffhausen onion cake in a preheated oven at 220 degrees
Goes well with a wonderful salad or a light soup beforehand