Clean the mushrooms and cut into thin slices. Peel and finely chop the onion. Heat the fat in a pan, fry the mushrooms and half of the onion. Season with a little salt and pepper and let it cool down. Meanwhile wash the chives, dab dry and cut into fine rolls.
Mix the crème-fraîche, quark and chives, except for a little bit for sprinkling. Season with salt and pepper, place in a small bowl and sprinkle with remaining chives. Clean, wash and drain the rocket and chicory. Halve the chicory and cut into strips. Wash, dab dry and dice the tomatoes. Mix clear herb sauce, 3 tablespoons of water and olive oil. Add remaining onion cubes and tomatoes. For the potato cookies, stir the contents of the bag into 1/4 litre of cold water with a whisk. Fold in the mushrooms immediately and let everything swell for about 5 minutes. Form a thick roll (approx. 5 cm Ø) with moistened hands and cut into 10-12 slices.
Add remaining onion cubes and tomatoes. For the potato cookies, stir the contents of the bag into 1/4 litre of cold water with a whisk. Fold in the mushrooms immediately and let everything swell for about 5 minutes. Form a thick roll (approx. 5 cm Ø) with moistened hands and cut into 10-12 slices. Heat the oil in a coated pan and fry the potato cookies until golden brown on both sides. Arrange hot potato cookies with rocket and chicory on a plate. Pour the tomato and herb vinaigrette over the salad and serve with the dip