This dish can be made and refrigerated the night before a brunch.
For a milder flavor, you can substitute 1 or 2 sliced large shallots for the onion.
While not authentic, you can add cheese or crumbled, cooked chorizo to your tortilla. Serve with warm, crusty bread. Anything goes!
If you'd like, the oil used for cooking the potatoes can be strained and reused. Just store oil in an airtight container in the refrigerator for up to 1 month. Use whenever oil is called for in your cooking needs—especially when sautéing meats, grains and vegetables!