Tortilla de patatas

Preheat the oven to 200 °C. Peel the potatoes and onion and slice them into 3 mm pieces. Arrange them on baking paper (try to prevent the slices from overlapping too much), drizzle lightly with oil, season with ½ teaspoon of salt, and bake for 15 minutes.

Crack the eggs into a bowl, season with the remaining salt, add ground pepper, and whisk. Add the roasted potatoes with onion and gently mix.

Pour a tablespoon of oil into a non-stick pan. Once it's hot enough, pour the mixture into the pan and fry for 4 minutes. Then cover the pan with a plate, turn the pan upside down to flip the tortilla out. Carefully slide the tortilla back into the pan to cook the other side. The cooking time depends on the height of the tortilla; a 22 cm diameter pan was used in this recipe. The tortilla is done when it springs back slightly when pressed; if it's completely firm, there's a risk it will be dry.