Which Spanish breakfast food is a thick omelette made mainly from eggs and potatoes?

The Spanish tortilla is a thick omelette made mainly from eggs and potatoes.

Known in Spanish as tortilla de patatas, it is prepared by cooking sliced or cubed potatoes, often with onion, in olive oil before combining them with beaten eggs. The mixture is then set in a pan and turned so that it forms a compact, round cake. It may be served hot, warm, or cold.

The dish is eaten throughout Spain and can appear at breakfast, as a tapa, or as part of a larger meal. Whether onion belongs in the classic version is a famous Spanish culinary debate, but potatoes and eggs are the core ingredients.

The Spanish tortilla should not be confused with a Mexican flour or corn tortilla. In English, “Spanish omelette” is often the clearest name because “tortilla” has different meanings across Spanish-speaking cuisines.