Clean and bathe fish. Pour heads, fins and bones with 4 cups of water and cook for 30 minutes, then filter the stock.

Cut onion into half-rings and fry on fat, then put potato and tomato cubes, add nutmeg, salt and pepper and fry for 1-2 minutes.

Then pour fried ingredients with fish stock and cook for 20 minutes. Then add fish fillet cubes and cook until fish done.

Remove the soup from the heat, season with greens and dress with sour cream.

Serve the fish soup with toasts.