Wash the potatoes, cook in boiling water for about 15 minutes, drain and rinse. Mix vinegar, mustard and stock, season with salt and pepper. Slowly stir in 1 teaspoon rapeseed oil
Peel and finely dice the shallot. Wash the chives and, except for a little bit for garnishing, cut into fine rolls. Stir the diced shallots and chives into the vinaigrette
Peel the potatoes and halve them lengthwise. Wash and halve the tomatoes. Wash and clean the rocket. Add potatoes, tomatoes and rocket to the vinaigrette and mix. Season potato salad with salt and pepper
Mix quark, lemon juice and zest, season with salt and pepper. Wash the meat, dab dry, season with salt and pepper. Heat 1 teaspoon of oil in a small coated frying pan, fry the meat for 1-2 minutes on both sides. Arrange salad with meat and quark and garnish with chives