Though in English this wonderful potato dish is known as a "Spanish tortilla" or a "Spanish omelette", it bears much more resemblance to a frittata than to a French omelette or to a Mexican-style tortilla. Torta española is a Spanish specialty, and like many Spanish dishes, it has found great popularity in Latin America. It's an example of simple comfort food at it best: a simple skillet combination of potatoes, onions and eggs. Torta espanola makes a wonderful one dish supper, but in Spain this dish is often served as an appetizer, cut into small pieces and enjoyed with crusty bread.
One distinctive feature of this dish is that the sliced potatoes and onions are first cooked in abundant olive oil, before they are mixed with the eggs and returned to the skillet. I have tried to make Spanish tortillas without frying the potatoes first, since deep frying potatoes in oil can be a messy and extravagant procedure, but the results were not the same. Pre-frying the potatoes is the key to achieving the unique taste and texture of this dish. The olive oil adds flavor to the potatoes and allows them to cook until they are soft, but not browned or crispy. Fortunately, even though you need a lot of olive oil to make this dish, you can strain the leftover oil (which is most of what you start with) and reuse it another time.
There is another little hitch to making a Spanish tortilla... You must be brave enough to flip the tortilla over in the skillet, in order to cook both sides. This is such a common dish in Spain that there is even a special platter called a vuelve tortilla to help with this step, but a large plate or even a wooden pizza peel will work just fine. You place the large plate/platter over the skillet, flip the skillet over so that the torta falls out onto the platter, then gently slide the now flipped torta back into the skillet so that the uncooked side is on the bottom. You do have to watch out for hot oil that might drip out of the upside down skillet, but other than that it's not too tricky. If you are feeling hesitant or don't have a large enough plate, you can always finish the torta off in the oven instead. Most importantly, always use a nonstick skillet (one that is also ovenproof, if you plan to finish the tortilla in the oven) when making Spanish tortillas.
Another nice thing about this dish is that you can add whatever extra ingredients you like to a Spanish tortilla, and it will only be the better for it. It's a great way to clean out the fridge. Chorizo sausage is a popular addition (see below). Vegetables are also good choices - peas and bell peppers are particularly popular. Cheese and herbs are also nice add-ins.
Enjoy these recipes for tortilla española. The first two include instructions for the traditional preparation method (i.e. frying the potatoes in olive oil and flipping the tortilla). Some of the other recipes use simpler preparation techniques, but as a result are not quite as authentic.Recipes:
Classic Spanish Tortilla with Chorizo
Classic Spanish Tortilla
Cheddar Potato Frittata - Torta Espanola con Queso
Spanish Tortilla with Sweet Potatoes and Bacon - Torta Espanola de Camote
Quick Tortilla Española