Classic Tortilla Española with Slow-Sweated Onions

⏱ 55 min · Serves 4

A thick, golden Spanish potato omelette with a just-set, custardy middle. Patience with the onions is the secret — they turn sweet and jammy, so every wedge tastes like a tapas bar in Madrid. Great warm, even better at room temperature with a glass of something cold.

Per serving: 425 kcal · 15.5g protein · 30.0g carbs · 27.0g fat

Ingredients

• 600g waxy potatoes (e.g. Charlotte or Yukon Gold), peeled
• 2 medium onions, thinly sliced
• 250ml olive oil (for confiting the potatoes; most is reused)
• 6 large eggs
• 1 tsp fine sea salt, plus more to taste
• Freshly ground black pepper
• Flaky salt and chopped parsley, to serve (optional)

Method

1. Slice the peeled potatoes into thin rounds, about 3mm thick. Pat them dry with a tea towel.
2. Heat the olive oil in a 22–24cm non-stick frying pan over medium-low heat. Add the potatoes and onions with 1/2 tsp salt. They should be just submerged — the aim is to poach, not fry.
3. Cook gently for 20–25 minutes, stirring occasionally with a spatula, until the potatoes are completely tender and break easily and the onions are soft and golden. Don't let anything brown crisply.
4. Drain in a colander set over a bowl, saving the oil (it keeps for a fortnight and is superb for roasting).
5. Beat the eggs in a large bowl with the remaining 1/2 tsp salt and plenty of pepper. Tip in the warm potatoes and onions, mash a few slices lightly with a fork, and let it sit for 10 minutes so the potato soaks up the egg.
6. Wipe the pan, return 1 tbsp of the reserved oil and set over medium heat. Pour in the mixture, spread level and cook for 4–5 minutes, easing the edges inwards with a spatula to build a rounded side.
7. When the base is set and the top still loose, slide the tortilla onto a large plate, invert the pan over it and flip it back in confidently. Cook 3–4 minutes more for a slightly soft centre, or 5–6 for firmly set.
8. Slide onto a board, rest 5 minutes, then scatter with flaky salt and parsley. Cut into wedges and serve warm or at room temperature.