Spanish Tortilla (Tortilla de Patatas)

Method

1. Peel the potatoes, cut them in half lengthwise and slice them 3 mm thick. Slice the onion into thin half-moons. Put both in a bowl, sprinkle with half the salt and toss well.

   Add in this stepWaxy or all-purpose potatoes 350 gOnion 100 gSalt ½ tsp

2. Pour the oil into a 18 cm nonstick frying pan (about 1.5 cm deep) and add the potatoes and onion; they should be almost covered. Heat over medium heat until small bubbles appear, then lower to medium-low heat and cook gently for 18 min, turning them now and then with a spatula. They are done when a slice breaks easily under the spatula: soft and pale, lightly golden in places, never crisp.

   Add in this stepOlive oil (for cooking the potatoes; most of it is drained off) 200 ml

   medium heat→medium-low heat

3. Set a sieve over a heatproof bowl and tip in the potatoes and onion to drain the oil (keep it, it is great for cooking). In a large bowl, beat the eggs with the rest of the salt until no streaks of white remain. Add the warm potatoes and onion, press them under the egg with a spoon and leave for 10 min so the potatoes soak up the egg.

   Add in this stepEggs 3Salt ½ tsp

4. Wipe the pan, add 1 tbsp of the drained oil and heat over medium-high heat for 1 minute. Pour in the mixture and spread it evenly; for the first 20 seconds, gently stir only the edges. Lower to medium-low heat and cook for 4 min, shaking the pan now and then and running the spatula around the edge. It is ready to flip when the edge has set and the underside is golden when you lift it slightly.

   medium-high heat→medium-low heat

5. To flip, place a flat plate larger than the pan upside down on top. Wearing an oven glove, hold the plate firmly and turn the pan over in one quick movement, over the sink. Add a few drops of oil to the pan and slide the tortilla back in, uncooked side down. Tuck the edges in with the spatula to round them and cook over medium-low heat for 2 min. When you press the centre it should feel springy but still slightly soft: that means juicy inside.

   medium-low heat

6. Slide it onto a plate and let it rest for 5 min so the centre settles. Cut into wedges and serve warm or at room temperature.