Place 1 tablespoon of olive oil in a large non-stick skillet and heat over medium-low heat.
Add onions and cook until soft, about 5 to 6 minutes before adding potatoes and more olive oil. Stir together and continue cooking until potatoes are soft.
Whisk eggs together in a medium-sized bowl. Add the potatoes and onions to the eggs and mix together. Season with salt and pepper. Add more olive oil to the pan and pour the mixture in. Cover with a lid and cook until eggs are browning on the edge.
Using a plate, flip the tortilla and slide back into the pan to finish cooking. Cook your desired doneness of the eggs.
Flip the tortilla out onto a plate and set aside to cool for a couple of minutes before slicing into wedges.