Spanish Tortilla

Peel the potatoes (600 g) and cut into thin slices, about 3–4 mm thick; slice the onion into thin half-rings.

Heat 80 ml olive oil in a wide skillet over medium heat, add the potatoes and onion, season lightly with salt, and cook for 15–18 minutes, stirring occasionally, until the potatoes are tender — they should be easy to pierce with a fork but not falling apart.

In a large bowl, whisk 6 eggs with salt and black pepper until well combined.

Using a slotted spoon, lift the warm potatoes and onion out of the skillet, letting the excess oil drain off, and add them to the eggs; gently fold together and let the mixture sit for 5 minutes.

Pour the mixture into the same skillet with a thin layer of the remaining oil, and cook over low heat for 6–8 minutes, until the bottom and edges set.

Cover the skillet with a large flat plate, flip the tortilla in one confident motion, and slide it back into the skillet raw-side down; cook for another 3–5 minutes, until the center is just barely moist but no longer runny.

Remove from the heat and let the tortilla rest in the skillet for 5 minutes before slicing.

Cut into wedges or slices and serve warm or at room temperature.