How to make
Clean and cut the fish fillets into pieces. Marinate them for 1 hour in lemon juice, vinegar and salt. Sauté the finely chopped onions in the oil and add 4 cups of cold water.
Put the fish, onions, black pepper and bay leaf in a pot. Leave the onion fish soup to boil for about 15 minutes. Remove it from the heat and once it cools slightly, thicken it with the beaten together eggs and yoghurt.
Temper carefully to prevent it from curdling. Finally, add the chopped parsley. Serve the fish soup with croutons.