Hard boil eggs, boil potatoes with peel. Put chicken and onion with salt in cold water and boil uncovered at high temperature.
Skim off foam and fat occasionally. Half cover the saucepan and continue cooking at moderate temperature for 60 minutes.
Peel and slice cooked potatoes. Remove the skin and bones from the chicken. Cut the meat into strips, mix with the potatoes.
Cut egg and cucumber into small pieces and stir in. Season to taste with salt and freshly ground pepper.
Mix sour cream and mayonnaise with a whisk and add to the lettuce. Decorate with olives, tomatoes and dill.