My wonderful Venezuelan friend Aymara sang the praises of the famous tortilla espanola. My thanks to her for introducing me to this wonderful national dish of Spain. It seems there are dozens of versions out there. My recipe is a collage of many recipes and suggestions.
I used less olive oil than usually suggested. I cooked the potatoes slowly in the oil, making sure to move the slices, ensuring they remain separate and do not brown too much. I cooked them "half way" to ensure the potatoes remain intact when the dish is served.
To serve four as a main course or many more as an hors d'oeuvre.
8 large eggs, room temperature
1 cup extra-virgin olive oil
1 1/2 lbs potatoes (Yukon Gold or russet) peeled, halved, and thinly sliced crosswise
3/4 lbs yellow onions, thinly sliced
In a large bowl, beat eggs vigorously with a large pinch of salt until frothy. Set aside.
In a 10-inch nonstick or well-seasoned carbon steel skillet, heat oil over medium-high heat until shimmering. Add the potatoes to gently bubble in the oil, cooking, stirring occasionally until almost tender, approximately 20 minutes. Set a fine-mesh strainer over a heatproof bowl and drain potatoes of excess oil. Reserve the oil.
Return a few tablespoons of the reserved oil back to the pan over medium heat. Add the onions. Cook gently until soft, not brown, approximately 15 minutes. Remove the onions from the pan.
Transfer the potatoes and onions to a medium bowl, stirring well to combine. Beat the eggs vigorously in a separate bowl, then add potato and onion and stir until thoroughly combined.
Wipe out the skillet. Add 3 tablespoons (45ml) reserved frying oil to skillet and set over medium-high heat until shimmering. Scrape egg mixture into skillet and cook, swirling and shaking pan rapidly, until bottom and sides begin to set, about 3 minutes. Continue to cook, adjusting heat to prevent the bottom of the tortilla from burning, until beginning to set around edges, about 3 minutes longer.
Place a large overturned flat plate or lid on top of skillet, set hand on top (using a dish towel if you are sensitive to heat), and, in one very quick motion, invert tortilla onto it. Add 1 more tablespoon (15ml) reserved oil to skillet and return to heat. Carefully slide tortilla back into the skillet and continue to cook until second side begins to firm up, about 2 minutes. Continue to cook the tortilla until lightly browned on second side but still tender in the center when pressed with a finger, about 2 minutes longer.
Carefully slide the tortilla out of the skillet onto a clean plate (or invert it onto a clean plate using the same method as before) and let stand at least 5 minutes before serving. Tortilla can be cut into wedges for a larger meal or into cubes for an hors d'oeuvre–sized snack.
Leftover tortilla can be refrigerated up to three days; allow to return to room temperature before serving.