Cover the potatoes and boil them in water for about 20 minutes. Bring milk and 1 pinch of salt to the boil. Simmer the pasta for about 10 minutes until the liquid is almost absorbed.
For the applesauce peel apples, quarter them, remove seeds and dice them. Steam with apple juice and 2 tbsp. sugar for about 10 minutes until soft. If necessary add more sugar. Leave to stand coarsely or mash to a fine puree as desired.
Peel onions and cut them into thin rings. Heat butter in a large pan. Fry the onions until golden brown.
Drain the potatoes, quench and let them cool down a little. Preheat oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). Grate cheese. Peel potatoes and dice them.
Mix the pasta and potatoes with a good 2/3 cheese, season with pepper and a little salt. Pour into an ovenproof dish. Spread onions over it. Sprinkle with the rest of the cheese. Bake Älplermagronen in a hot oven for 10-15 minutes until golden brown.
Add the applesauce.