Why is potato omelette day celebrated today, 9 March?

How do you like yours… with onion or without? However, there are many other options with peppers, tuna, tomato or mushrooms... the number of possibilities with a potato omelette are almost endless, it's just a matter of taste and imagination.

The popularity of the tortilla de patatas is so widespread the dish now has its own day in the international calendar of special events, and the chosen date is today - Thursday, 9 March.

• Giant-sized omelettes made by a Ukrainian chef in Malaga province

The potato omelette can be served as an appetiser, accompaniment or single dish, and its fans are numerous, but how it originally came about is still unknown. Some theories suggest that it was invented in 1604 by a Belgian priest, Lancelot de Casteau. However, others claim the Spanish origin of this staple dish in Spain and point out that it was invented in Extremadura, specifically, in the town of Villanueva de la Serena at the end of the 18th century in 1798. And in this municipality the tortilla is a very precious commodity and in summer they hold a fair with this dish as the centre of attraction.

Although numerous ingredients can be added, these are three pillars of the dish: fresh eggs, potatoes and a good oil.

It is recommended to use specific pans to prepare the dish and make sure that the tortilla fits snuggly in the pan. To turn it over, the omelette should be well protected with a thick cloth.