In Sardinian cuisine we find dishes that despite having different ingredients are called by the same name, while dishes with the same ingredients are called differently. Two dishes are called 'Sa merca' despite being made with different ingredients.
We often speak of 'merca' to indicate the Oristanese speciality of boiled mullet, defining it as a dish of Phoenician origin with the etymological meaning 'salted food'. The Phoenicians were a people who practised fishing and preserved their catch in salt.
Sa merca is also a Nuoro dish made only of curdled, soured milk and salt.
It is believed that the name 'merca' was given to the two dishes because they both share the same preservation method, namely that of salt. This preservation process was discovered and practised by prehistoric man.
The mullet was commonly caught in ancient times and the curd was the first great accidental discovery made by ancient man, solving the age-old problem of food preservation. (Taken from an article written by Giovanni Fancello, expert and lecturer in the history of Sardinian gastronomy and author of numerous publications, published on the website taccuinigastrosofici.it) (Tratto da un articolo scritto da Giovanni Fancello, esperto e docente di storia della gastronomia sarda e autore di numerose pubblicazioni, pubblicato sul sito taccuinigastrosofici.it)
RECIPE FOR SA MERCA DI CABRAS
Sa Merca (or Mrecca). This is a very simple dish made from mullet that is boiled and wrapped in a marsh herb called 'ziba' or obione, which corresponds to a variety of glasswort. Boiling and salting allows the dish to keep for a few days.
After scaling the mullet and removing the gall, cut them up and boil them in plenty of salted water. Drain them and wrap them in marsh grass leaves called 'ziba', leaving them like this for at least a day. (Taken from an article written by Claudia Sanna and published on marecalmo.org on 14/04/2017)