Cut the potatoes into cubes. Heat 1 tablespoon of oil in a coated pan. Fry the potatoes for about 15 minutes, turning occasionally. Salt the potatoes lightly
Wash the salmon fillet, dab dry, dice and sprinkle with lemon juice. Leave to stand for a while. Bring 1/8 litre salted water with mustard seeds and bay leaf to the boil. Let the salmon simmer for about 5 minutes at low heat. Remove with a skimmer. Clean the spinach and cut it up roughly. Mix sour cream, vinegar, mustard and rest of oil. Season to taste with salt, pepper and a dash of sweetener
Mix potatoes, spinach and fish and arrange on portion plates. Cover with the dressing and serve garnished with lemon slices