Put the egg, garlic, lemon juice, parsley, and onion in a blender or food processor and process until smooth, about 15 seconds. With the processor running, pour the oil through the feed tube in a steady stream. Add the mustard and Worcestershire, season with salt, pepper, and hot sauce, and pulse once or twice to blend.
Cover and let sit for 1 hour in the refrigerator before serving. Best if used within 24 hours.
Makes about 1 1/3 cups
Salmonella warning: Letís talk about egg safety because I donít want any of you out there to get sick. I personally love homemade fresh mayonnaise and I make it with freshóand I mean FRESHóraw eggs. Iíve never had any trouble, but I want you to take some precautions. Always purchase your eggs from a reputable source, a place you can trust with your life. Donít use eggs after the expiration date on the carton. Donít go leaving your eggs in the backseat of your car while youíre out and about, and once you get home, keep the eggs in the refrigerator. I use eggs pretty quickly, so I donít have to worry about keeping them too long at home. But I suppose thereís a tiny risk some nasty old salmonella could sneak into some eggs, so just be cautious about serving young kids or the elderly or to people who have health problems. Okay?