The key to a delicious Spanish tortilla is to get the right balance between the amount of potatoes and eggs. It is also crucial to soften the potatoes by lightly frying them in olive oil before stirring them into the beaten eggs.
Frying the potatoes
Note that you are not making potato chips here. Don’t expect the potato slices to brown and turn crisp. You don’t want to overcook them either until they fall apart when lifted. You just want to make sure that they are cooked all the way through.
So, what is the right balance between the amount of potatoes and eggs?
For me, 250 grams of potatoes, 150 grams of onions and four large eggs. That’s enough eggs to bind the potato and onion slices without the tortilla having too much of an egg-y taste. You can use any number of pieces of potatoes and onions, so long as the total equals the correct weight.
What kind of potato and onion?
I personally recommend starchy rather than waxy potatoes—the kind you’d make French fries with. For best results, use a mandoline slicer to get slices with uniform thickness. That’s not just for visual effect; slices with uniform thickness will result in even cooking. You don’t really want to have some slices that are mushy and others that are obviously undercooked.
For the onion, go for the sweet yellow ones. After cooking, the sweetness of the onion will give the seasoned eggs such a beautiful contrast.
- chopped parsley
- extra virgin olive oil
- Cut the potatoes into thin slices, about ¼-inch thick or, if you can manage it, even thinner. Use a mandoline slicer for best results.
- Do the same with the onions.
- Heat the olive oil in a frying pan. Over medium heat, fry the potato slices. Stir them around gently to make sure that no slices are sticking together.
- Add the onion slices to the potatoes. Continue frying until the potatoes are cooked through and the onion slices have softened.
- Strain the potato and onion slices.
- Pour the oil off the frying pan (you may reuse it) leaving only enough to coat the bottom lightly.
- Beat the eggs with salt and pepper in a mixing bowl. I use a generous pinch of salt and a small pinch of pepper for every egg.
- Add the potato and onion slices to the beaten eggs. Stir them gently to allow the beaten eggs to seep between them.
- Reheat the cooking oil in the frying pan. Pour in the egg, potato and onion mixture. Set the heat to low. Cover the pan. Allow the tortilla to cook for about ten minutes.
- Loosen the sides and bottom of the tortilla with a spatula. Check if the sides and bottom have browned nicely. At this point, the eggs will still be a little raw at the center but the sides should be firm.
- Place a plate (should be wider than the pan), upside down, on top of the pan. Pressing down on the plate with one hand and holding the pan with the other, invert the tortilla on the plate.
- Drizzle more olive oil to coat the bottom of the pan. Reheat. Slide the tortilla back into the pan, cover and cook for another five minutes.
- Cool the Spanish tortilla a little before slicing.