Directions

1. 1

   Peel the potatoes and cut them into 1/3-inch dice. Heat the olive oil in a 10-inch nonstick skillet over moderate heat until shimmering, then reduce heat to moderately low. Add the diced potatoes, chopped onion, and 1 teaspoon of salt. Cook, stirring occasionally, until the potatoes are fork-tender, approximately 20 minutes.

2. 2

   While the potatoes cook, bring a large pot of salted water to a boil. Add the kale and cook for 2 to 3 minutes until wilted. Drain the kale in a colander, then immediately plunge it into a bowl of ice water to stop the cooking process. Drain again thoroughly, then squeeze handfuls of kale to remove excess moisture. Coarsely chop the kale.

3. 3

   Stir the chopped kale into the potato mixture and cook, stirring occasionally, until the kale becomes tender, about 5 minutes. Pour the vegetable mixture into a colander set over a bowl to drain the oil, reserving the drained oil separately. Allow the vegetables to cool for 10 minutes.

4. 4

   Lightly beat the eggs in a large bowl. Stir in the cooled vegetable mixture, 1 tablespoon of the reserved drained oil, and the remaining 1/2 teaspoon of salt until just combined.

5. 5

   Add 1 tablespoon of the reserved drained oil to the skillet and heat over low heat. Pour in the egg and vegetable mixture, then cover and cook over low heat until the sides and bottom are set but the center remains slightly soft, about 12 minutes. Remove from heat, keep covered, and let rest for 15 minutes.

6. 6

   Gently shake the skillet to ensure the tortilla is not sticking; if needed, use a heatproof plastic spatula to loosen it. Slide the tortilla onto a large flat plate. Place the skillet upside down over the tortilla and flip both together so the tortilla returns to the skillet with the uncooked side down. Use a plastic spatula to gently round off the edges. Cover and cook over low heat for 10 minutes more. Slide the finished tortilla onto a serving plate and serve warm, cut into wedges.