How to Make It
In a medium saucepan, cover the potato with cold water and bring to a boil. Cook until tender, about 20 minutes. Let cool slightly, then peel and coarsely mash.
In a food processor, pulse the almonds with the garlic until minced. Add the potato and pulse just until combined. With the machine on, add the oil in a slow, steady stream. Add the vinegar and process until blended. With the machine on, add the sparkling water in a slow, steady stream and process until the Skordalia is creamy. Season with salt and white pepper.