Wash the potatoes, cook in salted water (1 teaspoon salt) with ground turmeric (1 teaspoon) and whole caraway (1 teaspoon) for about 20 minutes, drain, peel and cut into slices. Clean and wash the radishes and cut into thin slices. Peel, quarter and thinly slice the onion. Onion strips with radish slices, sunflower oil (2 tablespoons), light rice vinegar (2 tablespoons), sugar (1 teaspoon), medium-hot mustard (1 teaspoon), coarse sea salt from the mill (3 big pinches) and colored pepper from the mill (3 strong Pinches) in a bowl and mix well, add / fold in the potato slices, mix everything carefully and let the salad stand for a while.