Wash the potatoes, boil for 20 minutes, rinse and peel. Wash fish fillet, sprinkle with lemon juice and dice. Put into boiling salted water and let it simmer for 5 minutes at low heat. Drain. Wash the cucumber, quarter it lengthwise and cut into slices. Wash and quarter cherry tomatoes. Peel and quarter the onion and cut into strips.
Cut potatoes into slices. Mix vinegar with salt, pepper and sugar. Whip oil into it. Wash the dill, dab dry, chop finely and add to the vinaigrette. Mix the salad ingredients with the vinaigrette and leave to stand for a while. Arrange in a bowl