Tortilla Española (Spanish Omelet), the easier way

Directions

1. Peel the potatoes, slice as thinly as possible and halve or quarter the slices (depending on the size of the potato). Do the same with your onion. I find it easiest to halve the root, then slice thinly, then halve the resulting slices.
2. Heat the oil in a 10-12 inch heavy skillet (I prefer cast iron). Drop a slice of potato into the oil. When bubbles form at the edges, the oil is ready. Add the potatoes and onions all at once, and cook over low heat, stirring frequently. You are poaching the potatoes in the oil rather than frying them, which is why you want to cook over a low, gentle heat. This also minimizes sticking, (though I admit I always have some potatoes that cling to the pan).
3. Stir frequently to bring the cooked potatoes up from the bottom and turn the uncooked potatoes into the oil, ensuring that everything cooks evenly. The potatoes will go from opaque to hinting at a shimmering translucence.
4. When the potatoes are cooked, drain them over a deep plate–you’ll be reserving the oil.
5. As they cool, crack your eggs into a large bowl and beat them lightly.
6. Pour a few tablespoons of the reserved oil back into the pan and heat. When the oil is hot, dump the potatoes into the eggs, turn them to coat, and pour into the pan. Pat the mixture out evenly over the surface of the skillet.
7. Place a rack at the top level of your oven and heat the broiler.
8. Cook gently until the tortilla firms up around the edges, then slide under the broiler. Depending on how long your broiler has been preheating, this could take just two minutes or up to 5 minutes. Check after two minutes and every minute thereafter.
9. Remove, allow to cool to room temperature in the skillet, slice and serve.
10. Note you can reserve the extra oil in the refrigerator for other uses, though I admit I’m not very good about re-using it, despite best intentions. The prolific use of olive oil makes this dish a bit of a luxury, but I still find it worth it.