Defrost the prawns. Peel and wash the potatoes and boil them in salted water for about 20 minutes.
Melt the fat. Fry 2 slightly heaped tablespoons of flour in it. Add milk and cream while stirring, simmer for about 5 minutes. Wash the dill and, except for a little bit, cut it finely and stir it into the sauce. Season to taste with stock, salt and pepper.
Wash the fish and prawns, dab dry. Cut fish into 4 pieces. Sprinkle with lemon juice, season with salt and pepper. Put 3-4 tablespoons of flour on a flat plate. Turn fish in the flour, shake off excess flour.
Heat the lard in a coated pan. Fry the fish for 3-4 minutes on each side. Fry the prawns briefly while turning.
Drain the potatoes and let them evaporate briefly, add to the dill sauce. Arrange the fish with the shrimps and dill cream potatoes. Garnish with dill. Wash, quarter and add organic lemon.