Chef John’s Tortilla de Patatas

Prepare the Vegetables: Using a sharp knife or mandoline, thinly slice the potatoes and onion to approximately 1/8-inch thickness. (5 minutes)

Whisk the Eggs: In a large bowl, whisk together the eggs, 1/2 teaspoon of kosher salt, black pepper, and cayenne pepper (if using) until well combined. Set aside. (2 minutes)

Cook the Potatoes and Onions: Add 1/3 cup of olive oil to a large, non-stick skillet over medium-high heat. Add the sliced potatoes, onions, and remaining 1 teaspoon of salt. Cook, stirring occasionally, until the potatoes are tender and some are lightly browned. Cover the skillet between stirrings to trap moisture and speed up the cooking process. Adjust heat to medium if browning too quickly. (20-25 minutes)

Combine and Rest: Gently fold the cooked potato and onion mixture into the whisked eggs using a spatula. Ensure the vegetables are evenly distributed. Cover the bowl and let the mixture rest for 5-10 minutes. This allows the potatoes to absorb the egg mixture, resulting in a more cohesive tortilla. (5-10 minutes)

First Cook: Add the remaining olive oil to an 8- or 9-inch non-stick skillet over medium-high heat. Once the oil is shimmering, pour in the egg and potato mixture. Smooth the top with a spatula. Cook, covered, for about 4-5 minutes, or until the bottom is golden brown and the edges of the tortilla begin to set. (4-5 minutes)

Flip the Tortilla: Carefully slide the tortilla onto a plate. Place another plate on top of the tortilla and invert the plates to flip the tortilla. (1 minute)

Second Cook: Slide the tortilla back into the skillet. Cook, uncovered, for another 2-3 minutes, or until the tortilla is fully set. To test for doneness, gently press the center of the tortilla. It should spring back lightly when pressed. If it feels too soft, cook for a few more minutes. (2-3 minutes)

Serve: Slide the tortilla onto a serving plate. Serve hot, warm, or at room temperature. A garlic aioli makes a delightful accompaniment.