Quarter the potatoes and thinly slice the potatoes to 1/8-inch thickness. This is when a mandoline comes in handy, like OXO's Simple Mandoline Slicer.

Heat the oil in the OXO 12" non-stick pan over medium heat. Add potatoes and onions and cook; flipping periodically until potatoes and onions are softened, about 15-20 minutes.

Beat the eggs in a large bowl until they turn a pale yellow. Add a generous pinch of salt and black pepper.

Pour the egg mixture over the potatoes. Gently lift the potatoes mixture so that the egg mixture is evenly distributed throughout and give the pan a gentle shake. Let cook and set for about 3 minutes or until the bottom is lightly browned.

Flipping the tortilla is a little tricky since the pan is large, but the side handles on the pan make the flipping a little easier. Take a lightweight cutting board or a baking sheet pan and cover the pan. Make sure the board or pan is a tad wider than the pan. Grab the handles and grip the board/pan with your thumbs. Quickly flip the pan and rest the board/pan on the counter. Warning: Some excess oil may splatter. Place the pan back on the heat and slide the tortilla back in. Continue cooking until eggs are set, about 3 minutes.

Cool to room temperature, cut in wedges and serve.