A Spanish omelette made with eggs, potatoes, olive oil and salt. Sometimes other ingredients, such as peppers, chorizo, onion, tuna, asparagus and mushrooms, are added.
It's cut into wedges and eaten hot or cold, similar to an Italian frittata.
In Mexico, tortilla refers to a soft floury flatbread made from corn or wheat flour, or tortilla chips - the spicy triangular corn crisps served with salsa and guacamole.