Cook the potatoes for about 20-25 minutes (depending on size).
Core the avocado, remove and dice the pulp and mix with 2 - 3 tablespoons of lime juice. Core and finely dice the red peppers. Finely chop the bunch of lettuce herbs and the clove of garlic. Core the peppers and cut them into small pieces.
Mix the herbal quark, crème légère and the yoghurt together. Fold in all the ingredients and sprinkle with cress. If necessary, season with salt.