Preparation Lentils in boiling broth covered at low heat approx. 1 1/2 hours swell. Peel and wash potatoes and cook in boiling salted water for about 20 minutes. Then drain well, press through a potato press or mash finely.
Let it cool down a bit. In the meantime clean the beetroot vegetables, put aside tender, small leaves and wash the tubers. Cook unpeeled in boiling salted water, with the addition of 2 tablespoons of vinegar, some sugar and caraway seeds, covered for about 45 minutes.
Wash the chives, dab dry and cut into small rolls. Mix 200 g quark, sour cream and 2/3 of the chives and season to taste with salt, pepper and nutmeg. Knead potato mixture, remaining quark, flour and egg, season to taste and divide into 8 pieces.
Form flat cookies with floured hands. Heat 4 tablespoons of oil. Fry the biscuits in them in portions on each side for about 3 minutes until golden brown. Keep finished cookies warm. Drain the beetroot, rinse with cold water and remove the skin.
Halve or quarter the tubers depending on size. Drain the lentils and collect the stock. Mix 1/8 litre stock, remaining vinegar and oil. Season vinaigrette with salt, pepper and sugar and mix with the walnuts, beetroot and lentils.
Arrange salad, potato cookies and some chives dressing on plates. Garnish with remaining chives and beetroot leaves and serve with the rest of the dressing.