Spanish Omelette (Tortilla de Patatas)

Peel and thinly slice one onion.

Peel and slice three potatoes into approximately 3mm thick rounds. They should not be too thin or too thick.

Pour about half a liter of olive oil into a non-stick pan and heat it over high heat.

Add the sliced onions to the hot oil and cook for about 10-15 minutes until caramelized.

Add the sliced potatoes to the pan with the onions. Stir to coat them in oil.

Cook the potatoes and onions for about 10-15 minutes on high heat until they are caramelized and tender but not mushy. Stir occasionally.

Drain the potatoes and onions using a slotted spoon, reserving the oil. Place the cooked mixture into a large bowl with the beaten eggs.

Add sea salt to taste and mix the potato and onion mixture with the six beaten eggs. Let the mixture rest for about 15-20 minutes to allow the potatoes to soak up some of the egg.

Heat a clean non-stick pan with a little of the reserved oil over high heat.

Pour the tortilla mixture into the hot pan. Cook on high heat for about 1 minute.

Lower the heat to medium-low and cook for about 2-3 minutes, gently running a wooden spoon around the edges to ensure it's not sticking.

Place a plate over the pan, hold it firmly, and with a swift motion, flip the pan and plate together to turn the tortilla over onto the plate. Slide the tortilla back into the pan, cooked side up.

Cook for another 2-3 minutes on medium-low heat until golden brown and cooked through. You can check doneness by inserting a knife or toothpick; it should come out clean.

Slide the finished tortilla onto a serving plate. Let it rest for a few minutes before slicing into wedges and serving.