Spanish Tortilla

Name: Spanish Tortilla
Prep time: 35 min
Cook time: 25 min
Total time: 1 h
Cuisine: Spain
Ingredients: 750 g (1⅔ lb) waxy or all-purpose potatoes, e.g. Yukon Gold, Charlotte or Spunta; 1 large onion, about 200 g, thinly sliced; 250 ml (1 cup) olive oil, plus 1 tbsp; most is drained off and can be reused; 10 g (1⅔ tsp) fine sea salt; 6 large eggs

Thick potato and onion omelette, golden outside and just set within

Makes: one 24 cm tortilla
Hands-on: 35 min
Total: 1 h
Level: Some skill

Tortilla de patatas is potatoes and onions slowly poached in olive oil, then bound with eggs and cooked into a thick, golden cake. It's served in wedges, warm or at room temperature, and the slightly soft center is the point.

Ingredients

750 gwaxy or all-purpose potatoes (1⅔ lb)e.g. Yukon Gold, Charlotte or Spunta
1large onionabout 200 g, thinly sliced
250 mlolive oil (1 cup)plus 1 tbsp; most is drained off and can be reused
10 gfine sea salt (1⅔ tsp)
6large eggs

Diet: Vegetarian, Gluten-free, Dairy-free
Allergens: egg
Origin: Spain

Method

Peel the potatoes, quarter them lengthwise, and slice 3 mm thick.
Heat the oil in a 24 cm nonstick frying pan over medium heat. Add the potatoes and onion and half the salt; the oil should come most of the way up. Cook at a gentle bubble, turning occasionally, until the potatoes are completely tender but barely colored, 18–20 minutes. 20 min
Set a sieve over a bowl and drain the potatoes and onion, saving the oil.
Beat the eggs with the remaining salt in a large bowl. Add the hot potatoes and onion, stir and leave for 10 minutes so the eggs warm and thicken slightly.
Wipe the pan, add 1 tbsp of the saved oil and heat over medium-high. Pour in the potato mixture and spread evenly. Cook, shaking the pan and running a spatula around the edge, for 1 minute, then lower the heat to medium-low.
Cook until the base is golden and the top is mostly set but still wet in the middle, 4–5 minutes. 5 min
Place a flat plate larger than the pan upside down over it. With one hand on the plate and one on the handle, flip quickly so the tortilla lands on the plate.
Add a little more oil to the pan if needed and slide the tortilla back in, cooked side up. Tuck the edges in with the spatula.
Cook for 2–3 minutes for a soft, slightly runny center, or 4–5 minutes for fully set. 3 min
Slide onto a plate and let rest for at least 10 minutes before cutting into wedges.

Why it works

Gently poaching the potatoes in oil cooks them through until creamy without browning or drying them, and the oil carries their flavor into the eggs. Soaking the warm potatoes in beaten egg starts to thicken the eggs and helps bind the tortilla. A short, hot first cook sets the base and gives the golden crust; the inside is then cooked gently so it stays tender.

Common mistakes

Frying the potatoes until crisp: they won't absorb the egg. Keep them pale and soft.
Fear of the flip: use a plate bigger than the pan and do it decisively over the sink.
Cooking too hot after the flip: the outside burns before the inside sets.

Variations

Without onion: The onion-free version is equally traditional; use 850 g potatoes.

Make ahead and storage

Keeps 2 days in the fridge; serve at room temperature. Excellent in sandwiches (bocadillos).

Notes

Strain and save the cooking oil for frying; it's well flavored. If serving to the vulnerable, cook the center fully set.