Heat a skillet or pot over medium heat. While it heats, chop the onions. Add a layer of olive oil to the pan, add the onions, and cover.

While the onions cook, peel and slice the potatoes. Stir the onions occasionally until they reach your preferred golden color.

Transfer the onions to a bowl. Add a bit more olive oil to the pan, add the potatoes, and cover. Stir occasionally and gently mash the potatoes as they cook.

Add the eggs to the bowl with the onions. I was going to make one large tortilla, but decided to make two smaller ones, so I divided the mixture. Add salt and pepper, then add the potatoes—half in each bowl if dividing. Mix well while the skillet heats.