Which Spanish tapas dish consists mainly of potatoes, eggs, and onion?

Spanish tortilla is a thick omelette made mainly from potatoes, eggs, and usually onion.

The potatoes are typically sliced or cut into small pieces and gently cooked in olive oil before being mixed with beaten eggs. The mixture is then cooked in a pan and turned so that the omelette becomes set outside while remaining moist inside. It may be served warm, at room temperature, or cold as a tapa.

The dish is also called tortilla de patatas, meaning “potato omelette.” It is different from a French omelette, which is generally thinner and does not use potatoes as its defining ingredient. Whether onion belongs in the recipe is a famous culinary preference in Spain, but potatoes and eggs are the essential elements.

Spanish tortilla is one of the country’s most recognizable everyday foods. Bars may serve it in wedges, cubes, or inside bread as a bocadillo, while home cooks prepare it as a meal as well as a tapa.