Tortilla de Patatas is an absolute staple of every café in Spain. Made from eggs, potato and onion, nothing could be simpler or more delicious.
Peel the potatoes and slice them into 5mm (quarter inch) slices. Cut the slices into 2cm (1 inch) bits. Half fill a non-stick frying pan with vegetable oil (I usually use a pan that is bigger than the one I'll be making the tortilla in because it gives a bit more space for cooking the spuds), and turn on to medium heat. Add one piece of potato and if bubbles start rising from the bottom, the oil is hot enough. Add the rest of the potato and cook gently for about 10 minutes, being very careful not let them stick to the pan or to take on any colour. Finely slice and chop the onion, add it to and continue cooking for another 5 minutes. Check that the potatoes are tender, and drain the potato and onion in a colander lined with kitchen paper. Place in the fridge to cool down.
Break all the eggs into a bowl, add the salt, and whisk it all together. Add the potato and onion and mix thoroughly. Heat a thin film of oil in a 18cm (7 inch) non-stick pan on medium heat. Add the omelette mixture and stir briefly to make sure the potatoes are evenly distributed.
After about 5 minutes you should see the edge of the tortilla beginning to set. Using a flexible spatula, gently tease the the mixture away from the edge of the pan, and work the spatula underneath to loosen the bottom of the tortilla. Now (deep breath) you need to turn it. Place a circular dinner plate over the pan, and, holding the plate firmly in place, lift the pan and turn it over. Remove the pan and you should have the tortilla cooked side up on the plate. Slide it back into the pan and continue cooking. Shape the edge with the spatula so you get a nice curving edge. Turn the tortilla two more times, cooking and shaping in between, and then slide it onto a plate. The perfect tortilla is slightly runny in the centre. Good luck!
Cut yourself a big wedge and serve it with a chunk of fresh, crunchy baguette. Breakfast is served.