In a large non-stick skillet, heat the olive oil over medium heat. Add the thinly sliced potatoes and onions, ensuring they are mostly submerged or well-coated in the oil.

Gently fry the potatoes and onions for 15-20 minutes, stirring occasionally, until the potatoes are tender but not browned. Use a slotted spoon to transfer them to a colander to drain excess oil, and let them cool slightly.

In the same skillet, leave about 1 tablespoon of oil and cook the diced chorizo over medium heat for 3-4 minutes until crispy and the savory oils have released. Remove from heat and let cool slightly with the potatoes.

In a large mixing bowl, crack the eggs and whisk them together with the smoked paprika, ground cumin, kosher salt, and black pepper until well combined and frothy.

Gently fold the drained potato and onion mixture, along with the cooked chorizo, into the beaten spiced eggs. Let the mixture sit for 10 minutes so the potatoes absorb the flavorful egg mixture.

Heat a 9-inch non-stick skillet over medium-high heat with a teaspoon of the reserved chorizo oil. Pour the egg and potato mixture into the pan, spreading out the potatoes evenly with a spatula.

Reduce the heat to medium-low and cook for 5-7 minutes, running a heatproof spatula around the edges. Cook until the bottom is lightly browned and the sides are set, but the center is still slightly runny.

Place a large flat plate over the skillet. Quickly and confidently invert the skillet to flip the tortilla onto the plate, then carefully slide it back into the pan to cook the other side.

Cook for an additional 3-4 minutes until the tortilla is fully set and golden brown on both sides. Slide onto a serving plate and let it rest for 10 minutes before slicing into wedges to serve.