Wash potatoes thoroughly and cook in boiling salted water for about 20 minutes. In the meantime, wash the fish, dab dry, sprinkle with lemon juice and salt. Cut the fish into 12 strips (slices).
Peel, wash and grate the carrots. Clean, wash and dab dry the salad, put some large leaves aside. Pluck remaining leaves into bite-sized pieces. Mix yoghurt with vinegar, season with salt, pepper and sugar.
Drain the potatoes and remove the skin. Wash the dill, dab dry, put some flags aside and chop the rest finely. Heat 30 g lard in a pan and fry the potatoes in it until golden brown.
Finally sprinkle the chopped dill over it. In a second pan, heat 30 g lard and fry the fish in it for 4-5 minutes on each side. Peel and dice the onion. Leave the rest of the lard in a saucepan and fry the onion in it until transparent, add the sauce and bring to the boil.
Keep the sauce warm. Wash the lemon thoroughly and cut into thin slices. Mix carrots and salad. Spread the remaining leaves on 4 plates and arrange the salad on top. Put yoghurt marinade on the salad.
Arrange 3 fish strips, potatoes and some sauce on each plate. Garnish with the lemon wheels and the dill flags. Remaining sauce extra is enough.