Cut the white onion, add it to the potatoes. In principle, you can use the usual onions, this is a matter of taste.
Add sauerkraut to the cup.
I write approximate amount of cabbage, I always put it "by eye".
If you have cabbage without carrots, then you will need to rub one small raw carrot on a fine grater into vinaigrette.
Put the beans in a vinaigrette, pre-drain the liquid from it. In addition to this, I still wash the beans with cold water, let them drain and only then put them in salads.
Mix the vinaigrette, if there is a desire, add salt. We fill with fragrant sunflower oil. You can take any butter, but in my opinion, it is the aromatic oil that is most relevant here. Vinaigrette is ready, give it a bit of insistence and serve.