Tortilla

Directions

1. 1
   Put the oil in a large, nonstick, ovenproof skillet over medium heat.
2. 2
   About 3 minutes later, add a slice of potato; if bubbles appear, the oil is ready.
3. 3
   Add all of the potatoes and onion, along with some salt and pepper.
4. 4
   Turn the potato mixture in the oil with a wooden spoon and adjust the heat so that the oil bubbles lazily.
5. 5
   Cook, turning the potato mixture gently every few minutes and adjusting the heat so the potatoes do not brown, until they are tender when pierced with the point of a small knife, 15 to 20 minutes.
6. 6
   Meanwhile, beat the eggs with some salt and pepper in a large bowl.
7. 7
   Drain the potato mixture in a colander, reserving the oil.
8. 8
   Wipe out the skillet and return it to medium heat, along with 2 tablespoons of the oil.
9. 9
   Combine the potato mixture with the eggs and add to the skillet.
10. 10
    As soon as the edges firm upthis will take only a minute or soreduce the heat to medium-low and cook, undisturbed, for 5 minutes.
11. 11
    Insert a rubber spatula all around the edges of the cake to make sure it will slide from the pan.
12. 12
    Carefully slide it outthe top will still be quite runnyonto a plate.
13. 13
    Cover with another plate and, holding the plates tightly, invert them.
14. 14
    Add another tablespoon of oil to the skillet and use a rubber spatula to coax the cake back in.
15. 15
    Cook for another 5 minutes, then slide the cake from the skillet to a plate.
16. 16
    (Alternatively, finish the cooking by putting the tortilla in a 350F oven for about 10 minutes.)
17. 17
    Serve warm (not hot) or at room temperature.
18. 18
    Do not refrigerate.