The vinegar in this warm soup is the link wtih gazpacho. It is suprisingly good and easy to make, so is associated in Spain with emergencies!
The idea is to stretch fish for one or two people to make soup for six. It is better made with fish stock, but still good made with water.
To prepare the fish stock (optional)
Put the bones and heads from the fish, plus the optional ingredients for the fish stock in a pan with the water. Simmer for 25 minutes, while you peel and dice the potatoes
Strain the stock, return to the pan and add the potatoes and salt. Cook until tender, then add the fish, in small pieces, for the last 5 minutes. Remove the potatoes and fish to a serving bowl.
Let the stock cool down a little (this is where mayonnaise is made at home). Stir the stock into the mayonnaise, to make a creamy soup and pour over the potatoes and fish.
Check the seasoning, stir in the vinegar and serve warm. Sometimes a jug of vinegar is passet at table.
Spanish Seafood recipes: The long coastline of Spain, combined with the two archipelagos, the Balearics and the Canaries, ensures that fresh fish and shellfish are ubiquitous elements of the Spanish table.
Andalusia recipes: The Romans taught the Andalusians how to cultivate wheat and vines and used the fish from the seas to produce the best "garum" in the empire. The Arabs taught the Andalusians how to grow fruit and vegetables. They used irrigation systems and improved the cultivation of olive trees and the production of oil. Furthermore, the Greeks, Phoenicians, Carthaginians and Visigoths left their mark on the art, science, culture and gastronomy of Andalusia.