The potato omelet is a dish that unites and separates Spain. It is a debate that could almost be described as a state issue.

The Center for Sociological Research (CIS) surveyed Spaniards to provide data. 70.4% maintain that it should be cooked with onion compared to 20.9% who defend the opposite. The controversy extends into other areas of its preparation: should it be served individually or quartered? Do you use olive or sunflower oil? Does it have to be cooked on both sides? Are the ingredients mixed before pouring into the pan?