Wash the potatoes and cook covered for about 20 minutes. Quench, peel and let cool down a little
Boil up approx. 1/8 l water. Stir in broth and vinegar, season with mustard, salt and pepper. Fold in the oil. Cut potatoes into slices and mix with the marinade. Leave to stand for approx. 30 minutes.
Finely crumble the bread. Whisk egg, 2 tablespoons of water, salt and pepper. Wash meat, dab dry. Turn in flour, egg and breadcrumbs one after the other. Press the breadcrumbs
Place the fillets on a baking tray lined with baking paper. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 35-40 minutes. Turn over after approx. 20 minutes
Wash the tomatoes. Slice tomatoes and cucumber. Wash and finely chop the chives. Fold everything into the potatoes, season to taste. Arrange everything