This humble meal is endlessly versatile – serve it any time of day, hot or cold, as either the centerpiece of the meal or an appetizer. My family enjoys the tortilla as a make-ahead breakfast with a side of fruit or for dinner with roasted vegetables or a salad. It’s perfect for packed lunches too, as the tortilla tastes great at room temperature. Servings: 6-8 servings (10-12 when serving as an appetizer)
2poundsYukon gold or red potatoes* (preferably of similar size for even cooking; DO NOT USE RUSSET!)
1medium yellow onion, diced or thinly sliced
3tablespoonsolive oil, divided use
Kosher salt and freshly ground black pepper
8large eggs (I use 9 if a few seem to be on the smaller side)
⅓cup(30g) freshly grated Parmesan cheese
1tablespoon(14g) butter
Optional for serving: a sprinkle of flay sea salt and pepper; a drizzle of extra virgin olive oil,
Instructions
Place the whole, unpeeled potatoes in a medium pot. Cover with an inch or two of water and bring to a boil. Reduce the heat and simmer until the potatoes are just tender when pierced with the tip of a sharp knife, about 15 to 20 minutes, depending on the precise level of heat and size of potatoes. (Tip: You want the potatoes to be tender, but not so tender that they crumble when sliced.) Drain, remove to a plate or cutting board, let cool so you can comfortably touch them. Peel the skin with your fingers (it will slip off easily, and it's okay if you miss some spots), and then cut the potatoes into ⅛-inch slices. Thin slices create the best final texture. (Helpful hint: For easy transfer and cleanup later, I slice the potatoes on a dinner plate.)
Preheat the oven to 400℉.
Warm 1½ tablespoons of the oil in a 10-inch non-stick, ovenproof skillet – seasoned cast iron if possible – over medium heat. Add the onions, season with a pinch or two of salt, and sauté until lightly golden, about 8 minutes. Set the pan aside so the onions cool slightly.
In a large bowl, whisk the eggs until smooth. Add the cooked onions, sliced potatoes, and season with salt and pepper. (I use one very lightly rounded teaspoon Morton’s kosher salt and about ¼ teaspoon pepper; adequate seasoning is important given the simplicity of the ingredients.) Gently toss to combine and coat all the potato slices with egg. (Tip: The potatoes should not be sticking together – make sure the egg separates each slice. It may be helpful to add the potato slices with your hands, separating the slices as you go.)
Return the skillet (the one from which you just scraped out all the onions) to medium heat and add the remaining 1½ tablespoons oil and the butter. When the butter foams, pour in the potato-and-egg mixture, and pat it down so it's even on the top. Sprinkle the Parmesan cheese evenly over the top, and cook until the eggs set around the edges, 2-3 minutes, and then transfer the pan to the preheated oven. Bake until the eggs are just barely set in the middle and the tortilla is lightly browned around the edges, about 15-20 minutes. (The internal temperature should be closing in on 200℉.)
Remove the pan from the oven and let it cool for 5-10 minutes on the stovetop. Run a thin spatula or knife around the edge of the tortilla to loosen it, and then invert it onto a plate or platter. (Tip: I place a plate directly over the top of the pan and, with both hands holding the pan and the plate together, quickly but carefully flip the whole thing upside down so the tortilla pops out onto the plate.) If desired, drizzle the top with extra virgin olive oil and sprinkle with a pinch or two of flaky sea salt.
The tortilla may be enjoyed warm or at room temperature for breakfast, lunch, or dinner. Slice into wedges for entrée portions or into bite-size pieces for tapas.
Notes
*You want a waxy potato like a Yukon gold or red skinned potato, which are lower in starch and higher in moisture than other varieties. A standard baking potato, like a Russet, will crumble when sliced thanks to its drier, starchier makeup.*To peel or not to peel? I used to peel the potatoes before boiling but now leave the skins on. Once boiled, the skins will pull off easily with your fingers. So much easier than peeling first! Yukon skins are thin, however, so you could leave them on if preferred.Pan size is important: A 9-inch diameter pan runs the risk of overflowing, while a 12-inch pan will yield a thin tortilla and will cook faster.Optional for serving: Beyond an extra sprinkle of salt and a drizzle of extra virgin olive oil, Spanish tortillas are traditionally served unadorned. For those who enjoy the addition of a sauce, I recommend Smoked Paprika Aioli or Italian Salsa Verde.