- 1/2 cup extra virgin olive oil
- 1 pound russet potatoes (about 3 medium), peeled and sliced into 1/8-inch-thick rounds
- 1 medium onion, halved and sliced 1/8 inch thick
- 10 large eggs
- 1/4 teaspoon ground black pepper
1. Adjust an oven rack to the middle position and heat the oven to 425 degrees. Heat the oil in a 10-inch ovenproof nonstick skillet over medium heat until shimmering. Add the potatoes, onion, and 1/2 teaspoon salt, and stir to coat thoroughly. Cover and cook, stirring occasionally, until the potatoes and onion are soft, 8 to 10 minutes.
2. Whisk the eggs, pepper, and 1 teaspoon salt together until uniformly yellow. Pour the eggs over the potatoes, stir gently to combine, and continue to cook until the eggs begin to set, about 1 minute.
3. Transfer the skillet to the oven and bake until the eggs are cooked, the top is puffed, and the edges have pulled away slightly from the sides of the pan, about 9 minutes. Use a rubber spatula to loosen the tortilla from the skillet, then carefully slide it onto a cutting board. Slice into wedges and serve. (The tortilla can also be made up to 4 hours in advance and served at room temperature.)