Wash, peel and slice the potatoes. Bring a litre of water and salt to the boil in a pot, add the pasta and cook for ten minutes. After six minutes add potato slices and cook. Meanwhile grate cheese. Peel and thinly slice the onions. Drain pasta and potatoes and let them drain. Put hot noodles and potatoes into a mould, alternating with the grated cheese (three to four layers).
Sprinkle some cheese on top. Heat the fat in a frying pan and fry the onions, turning them golden brown. At the end of frying, place the onions with the frying fat over the cheese noodles. Wash the parsley and chop finely, except for a little bit for the garnish. Sprinkle over the noodles and serve immediately. Serve with fresh apple sauce or a green salad
Tip: The cheese should be melted by the dish's own heat before serving. You can also put the bowl in a warm oven for a few minutes, or cover the dish after the layers to make the cheese melt better.