As we all discovered over lockdown, eggs are incredibly useful things; a complete protein source, they’re cheap, versatile, keep well even out of the fridge and are, most importantly, delicious. This classic Spanish recipe is a good way to make them go further; satisfyingly filling, it’s almost as good cold in a sandwich as it is warm from the pan.
Prep 15 min
Cook 50 min
Serves 4 as a meal, 8 as tapas
1 medium onion (optional)
300ml olive oil
Salt and pepper
600g potatoes, preferably a waxy variety
6 medium eggs, beaten
2 tbsp extra-virgin olive oil
1 Onions, or no onions?
Start by peeling and finely slicing the onion, if using – many Spaniards prefer their tortilla without. You could also use spring onions, chives, or even shop-bought, Asian crispy fried shallots instead, but if so, simply chop and add to the egg mixture in step 5; there’s no need to cook them first.
2 Soften the onion
Heat the olive oil in a large frying pan over a medium-low flame, then add the onion and a pinch of salt. Stir to coat with the oil, then cook gently for about 20 minutes, until very soft and limp, and only just beginning to colour – if you don’t cook the onion enough, it will leak moisture into the omelette.
3 Now for the spuds
Meanwhile, prepare the potatoes; waxy varieties such as jersey royals or charlottes are ideal here, but you can just about get away with using whatever you have to hand. Peel and thinly slice them (if you have one, a mandoline or food processor would be handy). You could even use 100g ready-salted crisps instead of fresh potatoes; try to find thicker-cut ones, if possible, and add them straight to the eggs in step 5, rather than pre-cooking.
4 Sweat the potatoes
Rinse the potato slices in cold water to get as much starch off the surface as possible, then pat them as dry as you can in a clean tea towel, before adding to the onion pan; if the pan seems overcrowded, do this in batches. Cook until the potatoes are soft and on the verge of falling apart.
5 Finish the tortilla mix
Drain the contents of the pan and leave to cool a little.Keep the oil for your next omelette, or to reuse in other savoury cooking; remember to sieve it to get rid of any bits. Crack the eggs into a large bowl, beat well, season, then add the cooked onions and potatoes (or crisps). Leave to stand for 10 minutes, or longer, if you prefer a stronger onion flavour.
6 Start to cook the tortilla
Put a smaller frying pan, about 22cm in diameter, on a medium heat and add the extra-virgin olive oil (or use the same amount of the original cooking oil, if you prefer). Turn the pan to coat it all over with oil and, once it’s hot, add the egg and potato mixture; it should almost fill the pan.
7 Don’t touch the tortilla
Leave the tortilla mixture to cook, undisturbed, until the edges begin to come away from sides of the pan and it looks about two-thirds set. Loosen around the edge with a spatula or palette knife, then very carefully, and wearing oven gloves, put a lipped plate on top of the pan and flip it over. Slide the inverted tortilla and any liquid egg back into the pan. (Alternatively, leave it as it is and finish it off under a medium grill.)
8 Finishing touches
Continue to cook until the tortilla is springy to the touch; I like it best when it’s slightly liquid in the centre (if you plan to eat it cold – though why would you? – you may prefer to cook it all the way through). Leave to cool to at least warm before serving, to enjoy the best flavour.
9 Variations on the theme
Though even onions are a matter of hot dispute in Spain, in truth this is a very versatile recipe; replace some of the potatoes with slices of roast squash, strips of roast pepper or tomatoes, blanched and well dried greens or peas, tinned anchovies, strips of ham or fried bacon, or a little grated cheese; as long as it’s not too wet, it will be delicious.