As an Angeleno, I've always thought of a tortilla as a canvas for all kinds of Mexican ingredients and foods. It wasn't until recently that I discovered a tortilla in Spain was something entirely different. A tortilla española is a sort of omelette typically made with potatoes and onions but can include anything from peppers to chorizo. How such different foods got the same name I'm not sure, but I suppose the word tortilla was used to reference their similar shapes.
There are a couple of things tortilla española is infamous for:
1) the difficult flipping of the egg omelette and
2) the cups upon cups of olive oil used to make it
In this recipe, I've omitted the egg flip by using an oven to finish off the eggs. As for the olive oil, I'm using a fraction of what is typically used in Spain, but I think it still yielded unctuously delicious eggs!
– 8 large eggs
– 1 medium yellow onion, thinly sliced
– 2 medium waxy potatoes (like Yukon Gold) sliced into 1/6 inch thick disks
– 1/2 cup of olive oil
– salt and pepper to taste
Preheat your oven to 375 with the rack positioned to the highest level. In a cast iron skillet (or any other skillet if you don't have one) heat the 1/2 cup of olive oil on medium heat and start lightly frying the slices of potatoes in batches so they're not crowded in your pan. Cook for a couple minutes on each side until cooked through. Make sure they don't turn brown or turn mushy. Drain the potatoes in a colander.
Then sautee the sliced onions in the oil with a good pinch of salt for about 7-10 minutes so that they become soft and translucent. Remove these and pour out all the left over oil except keep a couple tablespoon of the oil in the pan. Layer down the onions in the pan and scatter the sliced cooked potatoes over. In a separate bowl, beat the eggs and add a hefty pinch of salt and some pepper. Return the pan onto the stove on medium heat and pour the egg mixture over it. Using a small fork or knife slightly lift the potatoes on all sides so the egg will run between the layers.
Cook for about 5 minutes on medium heat and then transfer into the oven with the rack placed on the highest level. Bake the eggs until they've set, about 8-10 minutes.
Let the tortilla rest and don't serve hot because it will fall apart. This should be served in wedges and the more time it has to set the better it will be!