Prepare the Potatoes:

• Peel the potatoes and slice them thinly (about 1/8-inch thick). If using onion, slice it thinly as well. Rinse the potato slices in cold water to remove excess starch, then drain.

Cook the Potatoes and Onion:

• In a large, non-stick skillet, heat the olive oil over medium heat. Once hot, add the sliced potatoes and onion (if using), stirring gently to coat in oil.
• Cook for about 15-20 minutes, stirring occasionally, until the potatoes are tender but not browned. Season with salt and pepper to taste. Once cooked, drain excess oil and set aside to cool slightly.

Beat the Eggs:

• In a mixing bowl, crack the eggs and whisk them until well combined. Season with a pinch of salt and pepper.

Combine Ingredients:

• Gently fold the cooked potatoes and onions into the beaten eggs, ensuring the potatoes are evenly coated. Let the mixture sit for about 5 minutes to allow the flavors to meld.

Cook the Tortilla:

• In the same skillet (wipe it clean if necessary), add a little more olive oil if needed and heat over medium-high heat.
• Pour the potato-egg mixture into the skillet, spreading it evenly. Cook for about 5-7 minutes until the bottom is set and lightly golden. To check, gently lift the edge with a spatula.

Flip the Tortilla:

• Place a large plate over the skillet and carefully invert the tortilla onto the plate. Slide it back into the skillet, uncooked side down. Cook for another 5-7 minutes until set and golden on both sides.

Rest and Serve:

• Once cooked, transfer the tortilla to a serving plate and let it rest for a few minutes. This helps the flavors develop and makes it easier to slice.
• Cut into wedges and serve warm or at room temperature. It pairs well with a simple salad or crusty bread.