You probably think about tacos, burritos and fajitas when you hear the word "tortilla." But in Spain, a tortilla is not a flatbread. It's a type of omelet. In Italy, it would be called a frittata.
This version is adapted from a recipe that appeared several years ago in Cook's Illustrated. The folks at America's Test Kitchen reduced the amount of olive oil significantly from the Spanish original. I was able to reduce it even more by using one of the new, super-nonstick "green" skillets.
I also halved the recipe, which makes the process of sliding the partially cooked tortilla onto a plate, flipping it onto another plate and then sliding back into the pan much easier. If you make the full recipe, use a 10- to 12-inch skillet and cook the potato-onion mixture for about 20 minutes instead of 15.
I added a bit of color and flavor to the tortilla by stirring in pieces of sun-dried tomatoes. You could also use cooked sausage or ham or cooked vegetables.
Serve Spanish tortillas warm or at room temperature for brunch, a light supper or as a nibble at parties alongside olives, serrano ham or prosciutto, chunks of manchego and other cheeses. I've even brought one to a potluck. In Spain, an almost infinite variety of tortillas are served at tapas bars along with numerous other tasty tidbits.
SPANISH TORTILLA (POTATO-ONION OMELET)
Yield: 2 entree or 4 appetizer servings
2 tablespoons plus 1 teaspoon extra-virgin olive oil, divided (see note)
12 ounces Yukon Gold potatoes (3 small or 2 medium), peeled, quartered lengthwise, and cut crosswise into 1/8-inch-thick slices
1/2 small onion, thinly sliced
1/2 teaspoon salt, divided
1/4 teaspoon ground black pepper
4 large eggs
1 1/2 tablespoons chopped sun-dried tomatoes, optional
Toss 1 tablespoon oil, potatoes, onion, 1/4 teaspoon salt and pepper in a medium mixing bowl until potato slices are separated and coated in oil.
Heat 1 tablespoon oil (see note) in an 8-inch nonstick skillet over medium-high heat until shimmering. Reduce heat to medium-low; add potato mixture. Cover skillet. Cook, stirring with rubber or silicone spatula every 5 minutes, until potatoes offer no resistance when poked with the tip of a paring knife, 15 minutes. (Some potato slices may break into smaller pieces.)
Meanwhile, whisk eggs with the remaining 1/4 teaspoon salt in the mixing bowl until just combined. Mix in the tomatoes.
Using the spatula, fold the cooked potato mixture into the eggs until combined, making sure to scrape all the potato mixture out of the skillet.
Return the skillet to medium-high heat. Add the remaining 1 teaspoon oil, and heat until just beginning to smoke. Add the egg-potato mixture and cook, shaking pan and folding mixture constantly for 15 seconds. Smooth the top of mixture with the spatula. Reduce the heat to medium, cover and cook, gently shaking the pan every 30 seconds until the bottom of the tortilla is golden brown and the top is lightly set, about 2 minutes.
Using the spatula, loosen the tortilla from the pan, shaking back and forth until the tortilla slides around freely. Slide the tortilla onto a large plate. Invert the tortilla onto a second large plate, then slide the tortilla browned-side up back into the skillet. Tuck the edges of the tortilla into the skillet with the spatula.
Return the pan to medium heat and cook, gently shaking the pan every 30 seconds, until the second side is golden brown, about 2 minutes. Slide the tortilla onto a cutting board or serving plate and let cool for at least 15 minutes. Cut the tortilla into cubes or wedges. Serve warm or at room temperature.
Note: This recipe was tested in an extremely slick nonstick skillet. If your skillet is not as slick, use up to 2 tablespoons oil when cooking the potatoes and onions.