To begin, heat the olive oil in a large skillet over medium heat. Once hot, add the sliced potatoes in batches, frying gently without browning. Stir occasionally to prevent sticking, cooking until the potatoes are soft (about 10-12 minutes).

Add the sliced onions to the skillet with the potatoes. Continue cooking for another 8-10 minutes, allowing the onions to soften and caramelize slightly without becoming crispy. This step develops the base flavours for a deliciously tender tortilla.

Once the potatoes and onions are tender, use a slotted spoon to transfer them from the skillet to a large bowl, letting excess oil drain back into the skillet. Season the potato-onion mixture generously with salt and pepper, stirring to coat.

In a separate bowl, crack the eggs and beat them lightly. Pour the eggs over the seasoned potato and onion mixture, gently folding until everything is evenly combined, taking care not to break up the potatoes too much.

Return about 1 tablespoon of the reserved oil to the skillet, reducing the heat to medium-low. Pour in the egg-potato mixture, spreading it evenly across the pan. Cook for 5-7 minutes, shaking the pan occasionally to prevent sticking, until the edges are set but the centre remains slightly runny.

To flip the tortilla, place a large plate over the skillet. Hold the plate firmly, flip the skillet to transfer the tortilla onto the plate, and slide it back into the skillet with the uncooked side down. Continue cooking for another 3-4 minutes, allowing the tortilla to cook through while remaining tender in the middle.

Once fully cooked, slide the tortilla onto a clean plate. Let it rest for a few minutes to settle and cool slightly before slicing. This resting period enhances the texture and makes slicing easier.

Serve the Tortilla Española warm or at room temperature, sliced into wedges. Traditionally, it’s garnished with a sprinkle of parsley and served with crusty bread or a simple side salad. For a Spanish touch, drizzle with a bit of extra virgin olive oil and pair with a glass of red wine.