Season the vinegar with sugar and salt, pepper and sugar, fold in the oil.
Peel the kohlrabi and cut into fine sticks. Clean and chop the lettuce, quarter the tomatoes, cut the cucumber into slices. Mix everything. Fold in the marinade.
Mix the sour cream and yoghurt until smooth, season with salt and pepper, fold in the cress.
Spread the lettuce on plates, place the eggs on top and pour the cress cream on top.