Classic Spanish Tortilla

A proper tortilla de patatas is nothing like a fry-up omelette. The potatoes are gently poached in olive oil until meltingly soft, then bound with beaten egg and cooked into a thick, golden cake with a barely-set, custardy middle. Serve it warm or at room temperature, cut into wedges.

The tortilla de patatas is the cornerstone of every Spanish kitchen and tapas bar. The secret isn’t speed but patience: potatoes and onion are confited slowly in plenty of olive oil until sweet and tender, never crisp. Bound with egg and flipped to a golden finish, it slices into wedges that are just as good cold the next day.

Ingredients

• 700g waxy or all-rounder potatoes — such as Maris Piper or Charlotte, peeled
• 1 large onion — halved and thinly sliced
• 250ml olive oil — for confiting; most is drained and reusable
• 6 large eggs
• 1 tsp fine sea salt — plus more to taste
• 1 tbsp extra virgin olive oil — for finishing the pan

Method

1. Cut the peeled potatoes in half lengthways, then slice into thin half-moons about 3mm thick. Don't rinse them; the surface starch helps the tortilla hold together.
2. Heat the 250ml olive oil in a 24cm non-stick frying pan over a medium-low heat. Add the potatoes and sliced onion with a good pinch of salt. They should sit almost submerged and barely bubble, gently poaching rather than frying.
3. Cook for 18-20 minutes, turning occasionally with a slotted spoon, until the potatoes are completely tender and give way easily when pressed, but still pale, not browned. Tip everything into a sieve set over a bowl to drain, saving the oil for another day.
4. Beat the eggs in a large bowl with 1 tsp salt. Fold in the warm drained potatoes and onion and let them sit for 5 minutes, so the egg soaks in and the mixture loosens. Taste and adjust the salt.
5. Wipe the pan, add the 1 tbsp extra virgin olive oil and set over a medium heat. Pour in the egg and potato mixture, spreading it level, and cook for 4-5 minutes, running a spatula around the edge to shape a neat curved side, until the base is set and golden and the top is still a little loose.
6. Slide the tortilla onto a large flat plate, cover with the pan, and confidently invert the whole thing so the tortilla drops back in cooked-side up. Cook the second side for a further 3-4 minutes.
7. For an authentic just-set centre, the tortilla should feel firm at the edges but yield softly in the middle when pressed; the outside is cooked through with no raw runniness, while the heart stays juicy. Slide onto a board and rest for 5 minutes before slicing into wedges.

Serve it with

• Crusty bread and alioli
• A simple tomato and red onion salad
• Marinated green olives
• A glass of chilled fino sherry
• Pan con tomate

Why this works

Poaching the potatoes low and slow in olive oil breaks them down to a sweet, silky texture that no amount of quick frying achieves, and resting the egg mixture lets everything bind into one tender cake rather than scrambled bits.

Common swaps

• Leave out the onion for a purist 'tortilla sin cebolla', a genuine Spanish debate in itself
• Add a handful of sliced roasted red pepper or wilted spinach with the potatoes
• Use a mild floury potato like King Edward if that's what you have; just cook until fully soft
• Swap a little of the finishing oil for a knob of butter for a richer edge

Common mistakes to avoid

• Frying the potatoes hot and crisp instead of poaching them soft, which gives a dry, chip-like tortilla
• Skipping the resting time, so the egg doesn't soak in and the tortilla falls apart
• Overcooking until the centre is completely dry; a slight wobble in the middle is the goal
• Using a pan that isn't properly non-stick, making the nerve-wracking flip stick and tear

Storage, freezing & reheating

Storage: Keep covered in the fridge for up to 3 days; the flavour actually improves overnight. Bring back to room temperature before serving for the best texture.

Reheating: Eat cold or at room temperature, or warm gently in a low oven or covered pan until just heated through; avoid a fierce heat that would dry it out.

Allergen notes: contains Egg. Always check individual product labels.

Estimated nutrition

Per serving, estimated from typical ingredient values — not a substitute for precise dietary calculation.