Wash the potatoes thoroughly and cut them lengthwise into halves or quarters. Fry them covered in 1/2 teaspoon hot oil for about 20 minutes. Season with salt and pepper
Clean or peel, wash and chop the vegetables. Add spring onion and carrot to the potatoes and fry open for another 10-15 minutes. Fry the mangetouts for about 3 minutes
In the meantime, wash the fish, pat dry and cut into pieces. Sprinkle with lemon juice. Season with salt and pepper and turn in flour. Heat 1/2 tsp. oil in a coated pan. Fry the fish for about 5 minutes while turning.
Wash and chop the chervil, except for something to garnish. Stir the sour cream into the vegetables. Season to taste with salt and pepper. Add fish. Garnish