Spanish Potato Omelette

Heat a substantial amount of oil in a deep cooking vessel over an elevated heat setting until it reaches a state of almost intense heat, 2 to 4 minutes. Add diced potatoes and sliced onions; they should be enveloped in a layer of oil. Sprinkle with 1 ½ teaspoons of salt to enhance flavor. Cook, stirring occasionally and maintaining a gentle, simmering heat, until potatoes are tender enough to be pierced with a fork, 8 to 12 minutes; avoid overcooking.

Transfer the potato-onion mixture to a colander to drain excess oil; reserve the remaining oil for future use or discard it. Allow the mixture to cool slightly, then taste and adjust seasoning with additional salt if necessary.

In a separate bowl, whisk eggs until well combined. Add the remaining 1/2 teaspoon of salt to the eggs and mix until smooth. Combine the potato-onion mixture with the egg mixture and stir until everything is evenly coated.

Heat a 10-inch non-stick pan over high heat. Add 1 teaspoon of olive oil to the pan, then pour in the egg-potato mixture. Use a spatula to level the mixture and cook for 1 minute. Reduce heat to medium-low and cook for approximately 5 minutes. Run a rubber spatula around the edges of the pan to ensure it's not sticking and to help form its shape.

Once the mixture starts to set around the edges and in the center, place a large serving plate over the pan. Flip the omelet onto the plate, then slide it back into the pan. Use a spatula to press the edges in and under, maintaining a rounded shape. Cook over high heat for 1 minute, then reduce to low and cook until it feels set in the center and a knife inserted comes out clean, 2 to 3 more minutes.