Tortilla
A tortilla is a perfect example of how a little technique can produce a dish that is greater than the sum of its parts. Using just potatoes, onions, eggs and some butter, they are one of the most delicious things to rustle up in your kitchen, with amazing depth of flavour. Before we go any further, I must say this is not an authentic tortilla, the keen eyed will notice I have replaced olive oil with butter, I love the rich nuttiness it adds and I’ve adapted the classic method to be easier in a home kitchen. So return the lifeless, dense, plastic packaged ones back to the supermarket shelf and follow this recipe to bring joy and wonderment to your kitchen table.
A true tortilla must be runny in the middle. The French have a word for this, ‘baveuse’, and it is key to tortilla success. It’s achieved by quick cooking over a high heat so the exterior browns but the centre stays soft. Another key component to tortilla perfection is the right choice of pan, too many people grab their workhorse large frying pans. However, in a wide diameter pan the mixture spreads out, reducing the thickness of the tortilla and so it overcooks with ease. To keep that tortilla unctuous, you need to reduce the diameter and increase the height. Get hold of a non-stick frying pan that is at most twenty centimetres across and at least four centimetres deep.
Due to the fact that not all pans are equal, I’m not going to give exact quantities on the ingredients. This is a good opportunity to step away from a recipe and start cooking by eye and feel. To achieve this, I take my pan of choice and place enough potatoes inside it to fill the pan. For a twenty centimetre pan this is usually around five hundred grams. Next you need one third of the amount of onions to potatoes, around one to two depending on their size. And finally for the eggs, it’s important to consider this isn’t an omelette with potato and onion, the egg isn’t the predominant ingredient - it is there to bind and hold the dish together. I find that three is the right amount for this size.
My tortillas start with the potatoes, it’s important to choose a waxy potato so they maintain their shape. I like to use a smaller potato, with yellower varieties also having a higher sugar content which adds a nice sweetness to the dish - look out for Jersey Royals, La Ratte or Charlotte varieties. A good tip is to batch cook a bag and store them in your fridge ready to quickly fry, add to salads, or use in tortillas. For the perfect tortilla you want to peel your potatoes, I’m usually a fan of keeping skins on, but the texture is jarring to the decadence of the tortilla if you don’t peel them. Once peeled, put them whole into a pan of cold, salted water, bring to the boil and cook them until they are very tender. It's my personal belief that waxy potatoes can’t be overcooked and I prefer to extend the cooking time to at least forty five minutes. Floury potatoes collapse if given too long, but waxy varieties become creamy, soft and delicious. The longer the better for the waxies - that’s one of my potato secrets. Cook them until they are completely tender.
Whilst the potatoes are cooking you can move on to the next key part of this recipe, the onions. There is only one way to cook these and that is low and slow. This should take at least forty five minutes, which is handy as that’s how long you’ll be cooking the potatoes for. First, cut your onions up, lyonnaise. This means halving, top and tailing and then slicing lengthwise into strips of around four millimetres, this holds the onion’s integrity as they cook down. You want to use a wide, heavy-bottomed saucepan to cook the onions. It will provide consistent heat at a low temperature for an even cook and the high side of a saucepan helps to regulate the heat and prevent over-browning by holding more moisture inside the pan. Place your saucepan on a low heat, add a good helping of butter (at least eighty grams) before adding the onions and a good pinch of salt. The salt draws the moisture out of the onions, which is important as the sugars in the onion will only start to caramelise once the water has been driven off. This takes time and can’t be rushed, this is the difference between the best onions you’ve ever made and ones that taste like they’ve come from a hot dog stand. Stir them every five minutes or so to help the onions cook down and to ensure contact with the bottom of the pan, you will notice they reduce dramatically by volume as they cook. They are ready when they are a lovely deep golden brown throughout, it’s important that they don’t blacken or burn, so reduce the heat if they take colour on too quickly. When they are done, remove them from the saucepan and place into a mixing bowl.
By now your potatoes should have cooked, or you’ll have some pre-prepared ones. Slice them into thick coins, around seven millimetres. Turn the heat up on the pan you cooked the onions in, add a little more butter and give the potatoes a quick fry. You’re looking to add colour and buttery flavour to them, once achieved add to the mixing bowl with the onions. While this is happening, take your eggs, break them into a separate bowl and give them a really good mix so the yolks and whites are thoroughly incorporated. Then add the eggs to the mixing bowl of onions and potatoes, combining thoroughly and seasoning with salt. The residual heat from the hot onions and potatoes will start the cooking process on the eggs, and the flavours will begin to infuse.
Now to get that frying pan that you’ve picked up especially to make your tortilla and place it over a high heat. It’s key to get it up to temperature before putting anything in the pan, otherwise you won’t get any browning. Once it’s hot, add a large knob of butter, letting it fully melt and begin colouring slightly. Now pour in the tortilla mixture. As the tortilla begins to cook you are looking for the edge to set by around half a centimetre, this should happen quite quickly. Now you need to flip it, the middle will still be runny and it will seem too soon, but trust that the time is right. Place a large plate over the pan and flip upside down, out onto the plate. Get the pan back on the heat, add a little butter again making sure the pan gets up to heat before then sliding the tortilla off the plate and back into the pan. This will be a slightly messy task, leaving a fair amount of residue on the plate, but worry not. Once it is back in the pan use a spatula to just push the sides down around the edges to neaten it up and then cook for the same amount of time the first half took. You are looking for a lovely golden brown colouring to the exterior, which can take a little practise, but it’s better to err on the side of removing it sooner as the most important thing is to not overcook the middle. When ready, flip it out again onto a clean plate and leave it to rest for a few minutes. There is residual heat inside the tortilla and this will continue to cook through, often termed as ‘carryover cooking’.
Proudly take your tortilla to the table and serve slices to your loved ones, it’s fabulous alone or can be accompanied with a very simple watercress, shallot and vinaigrette salad and most importantly, a glass of wine.