Tortilla de Papas
10 large eggs 2 tsp kosher salt 2 lb gold potatoes (about 6?), peeled and cut into 1/4" slices 2 cups evoo 1 large onion, halved, thinly sliced lengthwise
Beat eggs, pepper, and 1 tsp. salt in a large bowl; set aside.
Pat potatoes dry with a clean towel. Heat oil in a large nonstick skillet over medium-high. Cook potatoes, turning occasionally, until tender, 8β10 minutes (you can cover the skillet in the beginning; the potatoes should be white, not brown). Add onions in batches and cook, stirring occasionally, until softened, 4β6 minutes. Using a slotted spoon, transfer potato mixture to a rimmed baking sheet and let cool slightly. Strain oil into a heatproof bowl. Wipe out skillet.
Beat eggs again until frothy. Add potato mixture to eggs; season with 1 tsp. salt. Heat ΒΌ cup reserved oil in same skillet over medium-high (chill remaining oil and reserve for another use). Add egg mixture, arranging potatoes to submerge. Reduce heat to medium and continue to cook, making sure potatoes are submerged but mostly undisturbed, until eggs are almost set and top is still slightly runny, 15β20 minutes.
Invert tortilla onto a large plate, then slide back into skillet browned side up. Cook over medium heat until golden on the bottom and cooked through, about 5 minutes more.
Cut into wedges. Serve warm or at room temperature.
Do Ahead: Tortilla can be made 2 hours ahead. Let stand at room temperature.