Tortilla can be found on most tapas menus but, despite the basic simplicity of the ingredients, making a good one is not guaranteed.
1 kg potatoes
200 g onion, chopped
8 eggs, 50 g each
1 dl olive oil, maximum acidity 0.4º
salt
Peel the potatoes and cut them into thin slices. Heat the oil in a non-stick frying pan (25 cm in diameter) and add the potatoes. Cook for 5 minutes then add the onion and salt.
Maintain over a high heat and occasionally stir the potatoes with a spatula to make sure that they do not stick, moving them from the frying pan surface up to the top. When they are soft, strain them in a colander. Mix the potatoes with the beaten eggs, stirring once and adding salt to taste.
Heat 3 tablespoons of the remaining oil in the frying pan and when it begins to smoke pour in the mixture. Shake the frying pan gently so that the omelette does not stick and shape the edges using a skimmer. Lower the heat and leave the omelette to set slowly.
When soft and juicy inside, flip on a plate and slide back into the frying pan to brown the other side for a few seconds.