Put 1/2 litre of water, vinegar and flour in a bowl. Brush the black salsifies under running water, peel them, cut them into approx. 2 cm pieces and place them in flour vinegar water. Bring salted water to the boil in a wide saucepan.
Add black salsifies, cover and cook for about 10 minutes until firm to the bite.
Clean, wash and chop the savoy cabbage. Peel and slice the carrots. Peel and finely chop the onions. Heat 2 tablespoons of oil in a large pot. Sauté the onions in it. Add the carrots and deglaze with stock and white wine.
Simmer gently for about 3 minutes. Add the savoy cabbage and black salsify and simmer for another 4 minutes.
Season stew with salt, pepper and nutmeg. Cut pumpernickel into small cubes. Heat 2 tablespoons of oil in a frying pan. Fry the pumpernickel until crispy. Remove and drain well.
Wash the chives, shake dry and cut into fine rolls. Arrange stew in bowls. Sprinkle with pumpernickel and chives.